A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z             ADSL Asymetrical Digital Subscriber Line A technology for transmitting digital information at high bandwidths on existing phone lines. Unlike regular dialup phone service, ADSL provides a continously-available connection. ADSL is asymmetric in that it uses most of the channel to transmit downstream to the user and only a small part to receive information from the user. ADSL simultaneously accommodates analog (voice) information on the same line. ADSL is generally offered at downstream data rates from 512 Kbps to about 6 Mbps.   ANSI American National Standards Institute An independent non-profit organization that creates and publishes U.S. national standards (such as Fortran, C, CGM, and so forth) taking input from all sectors of the technical community and the public at large. ANSI also works in collaboration with other standards organizations such as ISO (the International Standards Organization).   API Application Program Interface A set of routines that an application uses to request and carry out lower-level services, e.g. services provided by the computer's operating system.   ASCII American Standard Code for Information Interchange This is the de facto world-wide standard for the code numbers used by computers to represent all the upper and lower-case Latin letters, numbers, punctuation, etc. There are 128 standard ASCII codes each of which can be represented by a 7 digit binary number: 0000000 through 1111111, plus parity. The values 0 to 31 are used for non-printing control codes, and the range from 32 to 137 is referred to as the standard ASCII character set. All computers that use ASCII can understand the standard ASCII character set. The extended ASCII character set (from code 128 through code 255) is assigned variable sets of characters by computer hardware manufacturers and software developers, and is not necessarily compatible between different computers.   ASP Active Server Page Microsoft's technology to enables HTML pages to be dynamic and interactive by embedding scripts, i.e. either VBScript or JScript, Microsoft's alternative of JavaScript. Since the scripts in ASP pages (suffix .asp) are processed by the server, any browser can work with ASP pages regardless of its support for the scripting language used therein. Introduced by Microsoft in the mid-1990s, this is the standard programming system for Internet applications hosted on Windows servers. It is bundled with Internet Information Server (IIS) when you buy Windows. The fundamental idea is that you write HTML pages with little embedded bits of Visual Basic, C# or other languages, that are interpreted by the server. B    top top   BBS Bulletin Board System A computerized meeting and announcement system that allows people to carry on discussions, upload and download files, and make announcements without the people being connected to the computer at the same time.   BIOS Basic Input/Output System A chip located on all computer motherboards that contains instructions and setup for how your system should boot and how it operates.   BIT Binary digIT The smallest unit of data in a digital system. A bit is a single one or zero. A group of bits, such as 8-bits or 16-bits, compose a byte. The number of bits in a byte depends upon the processing system being used. Typical byte sizes are 8, 16, and 32.   BMP Bit Mapped Pattern The standard graphics file format on Windows-compatible computers. Bitmap graphics support 24-bit color.   BOOTP Bootstrap Protocol a UDP network protocol used by a network client to obtain its IP address automatically. It is usually done in booting process of computers or operating systems running on them. The BOOTP servers assign the IP-address from a pool of addresses to each client with a certain lease time. It is originally defined in RFC 951.   bpi Bits per inch A measure of how densely information is packed on a storage medium.   bps Bits per second The standard measure of data transmission speeds. A "bit" represents the smallest unit of data in a computer; 8 bits make up one byte, which can represent a character like "A" or "3". Usually not bps will be mentioned but Kbps, for kilobits per second. If you have a 28.8 Kbps modem, it means that your modem can transmit at speeds up to 28,800 bits of information per second. C    top top   CAD Computer Aided Design The use of a computer in industrial design applications such as architecture, engineering and manufacturing.   CAM Computer Aided Manufacturing The use of computer aids (hardware and software) in planning, tracking, analyzing, and implementing the construction of manufactured items.   CD Compact Disc A standard medium for storage of digital data in machine-readable form, accessible with a laser-based reader. CDs usually are 4-3/4'' in diameter. CDs are faster and more accurate than magnetic tape for data storage. Faster, because even though data is generally written on a CD contiguously within each track, the tracks themselves are directly accessible. This means the tracks can be accessed and played back in any order. More accurate, because data is recorded directly into binary code; magnetic tape requires data to be translated into analog form. Also, extraneous noise (tape hiss) associated with magnetic tape is absent from CDs.   CDF Channel Definition Format A push technology based on XML syntax (submitted to W3C by Microsoft and Marimba). CDF is an XML vocabulary designed to specify metadata about Web pages which will enable filtering to create "Web Push Channels". With CDF, we can describe content ratings, scheduling, logos, and abstract information. Today, the channels we see in browsers are powered by XML and the CDF vocabulary. Instead of a user pulling information from a server, the user sets the channel and receives updated information.   CGI Common Gateway Interface A set of rules that describe how a Web Server communicates with another piece of software on the same machine, and how the other piece of software (the "CGI program") talks to the web server. Any piece of software can be a CGI program if it handles input and output according to the CGI standard. Usually a CGI program is a small program that takes data from a web server and does something with it, like putting the content of a form into an e-mail message, or turning the data into a database query.   CMS Content Management System A software program [application] designed to store, format, reproduce and manage Web/intranet data. The CMS usually uses a database to store the content and a server-side scripting language to recall and present the data. A CMS allows the content manager or author of the website, who may not know HTML the programming language used for the web, to create, modify, remove and organize the information, pictures etc. on their website.   CODEC COmpressor/DECompressor Codecs are applied to audio, video and image files to compress their size. The benefit is that the files don't use as much disk space when stored or as much network bandwidth when streamed. To open a compressed file, the same codec must be used to decompress the file.   CPU Central Processing Unit Also known as a computer processor or microprocessor the CPU was first developed by Intel in 1974. The computer CPU is responsible for handling all instructions and calculation it receives from other hardware components in the computer and software programs running on the computer.   CRM Customer Relationship Management Aan information industry term for methodologies, software, and usually Internet capabilities that help an enterprise manage customer relationships in an organized way. For example, an enterprise might build a database about its customers that described relationships in sufficient detail so that management, salespeople, people providing service, and perhaps the customer directly could access information, match customer needs with product plans and offerings, remind customers of service requirements, know what other products a customer had purchased, and so forth.   CRT Cathode Ray Tube A video monitor based on cathode ray tube technology. The CRT fires an electron beam that strikes the inside of the monitor's display surface, which is coated with phosphor. The phosphor glows briefly when "excited" by the beam. Color CRTs have a shadow mask that the beam passes through on its way to the phosphor. The shadow mask ensures that the guns excite only phosphors of the color on which they were fired.   CSS Cascading Style Sheets Style sheets when attached to documents describe how the document is displayed or printed, e.g. a CSS sheet is attached to an HTML document, to influence its layout when accessed via a browser. CSS supports cascading, i.e. a single document may use two or more style sheets that are than applied according to specified priorities (=cascade).   CSV Comma Seperated Values Data tables that are presented in Comma Delimited, CSV text file format. Although this file format allows for the data table to be easily retrieved into a variety of applications, they are best viewed within one that will allow one to easily manipulate data that is in columnar format. Common examples of such applications are those that are used to create spreadsheets and databases. D    top top   DAT Digital Audio Tape a certain type of digital tape, resembling a small videocassette, on which one can record stereo audio and subcoded index and time information. The high audio quality at a (relatively) low price made DAT a defacto standard in the music industry in the 1990s, from amateur musicians to major studios. Recordable CDs have made DATs less prevalent.   DBMS DataBase Management System A collection of computer programs that allow storage, modification, and extraction of information from a database. There are many different types of DBMSs, ranging from small systems that run on personal computers to huge systems that run on mainframes.   DDoS Distributed Denial of Service On the Internet, a denial of service (DoS) attack is an incident in which a user or organization is deprived of the services of a resource they would normally expect to have. Typically, the loss of service is the inability of a particular network service, such as e-mail, to be available or the temporary loss of all network connectivity and services. In the worst cases, for example, a Web site accessed by millions of people can occasionally be forced to temporarily cease operation. A denial of service attack can also destroy programming and files in a computer system. Although usually intentional and malicious, a denial of service attack can sometimes happen accidentally. A denial of service attack is a type of security breach to a computer system that does not usually result in the theft of information or other security loss. However, these attacks can cost the target person or company a great deal of time and money.   DHCP Dynamic Host Configuration Protocol A utility that enables a server to dynamically assign IP addresses from a predefined list and limit their time of use so that they can be reassigned. Without DHCP, an IT Manager would have to manually enter in all the IP addresses of all the computers on the network. When DHCP is used, whenever a computer logs onto the network, it automatically gets an IP address assigned to it.   DMOZ Directory Mozilla The original name for the Open Directory Project (ODP). DMOZ is an acronym for "Directory Mozilla", which reflects the directory's loose association with the Netscape Mozilla project.   DNS Domain Name System (or Service or Server) An Internet service that translates domain names into IP addresses.   DOM Document Object Model A platform- and language-neutral interface that will allow programs and scripts to dynamically access and update the content, structure and style of documents. The document can be further processed and the results of that processing can be incorporated back into the presented page.   DOS Disk Operating System An operating system developed by Bill Gates for personal computers. Microsoft (MS) DOS is a command line user interface. MS-DOS 1.0 was released in 1981 for IBM computers and the latest version of MS-DOS is MS-DOS 6.22, which was released in 1994. While MS-DOS is not commonly used by itself today, it still can be accessed from every version of Microsoft Windows by clicking Start / Run and typing "command" or by typing "CMD" in Windows NT, Windows 2000 or Windows XP.   DRAM Dynamic Random Access Memory A type of semiconductor random access memory that stores information in integrated circuits that contain capacitors. Because capacitors lose their charge over time, the dynamic RAM must be periodically "refreshed" or recharged. Contrast with SRAM. See also VRAM.   DSL Digital Subscriber Line A technology that uses ordinary copper telephone lines to provide Internet speeds ranging from 1.5 to 9 Mbps--speeds that are 30 to 50 times faster than a regular 56-kbps dial-up modem. DSL also allows users to receive voice and data simultaneously, since the signal is carried on a higher frequency than normal telephone communications. xDSL refers to all types of Digital Subscriber Lines.   DTD Document Type Definition The purpose of a DTD is to define the legal building blocks of an XML document. It defines the document structure with a list of legal elements.   DVD Digital Versatile (Video) Disc An optical storage medium that can store up to 4.7 Gigabytes (single layer), 8.5 GB (double layer), 9.4 GB (double sided, single layer), or 17 GB (double sided, double layer). Transfer rates and seek times are similar to those of CD-ROM for currently available drives. The DVD spec included higher level specs for audio and video capabilities. One of the best features of DVD drives is that they are backward-compatible with CD-ROMs. E    top top   EBCDIC Extended Binary Coded Decimal Interchange Code A character encoding scheme used by IBM mainframe computers and some other computers. Unlike ASCII, the EBCDIC standard specifies use of the entire 8 bits of each byte. Example: in EBCDIC the number seven is treated as a character and is encoded as: 11110111. EBCDIC coded character sets reserve the first 64 code positions (x00 to x3F) for control codes, and reserve the range x41 to xFE for graphic characters. The English alphabetic characters are in discontinuous segments with uppercase at xC1 to xC9, xD1 to xD9, xE2 to xE9, and lowercase at x81 to x89, x91 to x99, xA2 to xA9.   EDI Electronic Data Interchange Version of electronic commerce between buyers and suppliers, using a set of standardized electronic business documents, which are exchanged in agreed upon formats. More cumbersome and costly than Internet-based commerce, feasible only for large companies and their most significant trading partners.   EMS Enhanced Messaging Service An adaptation of the Short Message Service (SMS) that allows users to send and receive ring tones and operator logos, as well as combinations of simple media to and from EMS-compliant handsets. Because EMS is based on SMS, it can use SMS Centers (SMSCs) the same way that SMS does. EMS works on all Global System for Mobile communications (GSM) networks (widely used in Europe and increasingly available elsewhere). If a message is sent to a phone that is not EMS-capable, the recipient will still receive the text portion of the message. F    top top   FAQ Frequently Asked Questions Documents that list and answer the most common questions on a particular subject. Read FAQs before wasting electrons asking obvious questions.   FAT File Allocation Table A file system that was developed for MS-DOS and used in consumer versions of Microsoft Windows up to and including Windows Me. The FAT file system is considered relatively uncomplicated, and because of that, it is a popular format for floppy disks; moreover, it is supported by virtually all existing operating systems for personal computers, and because of that it is often used to share data between several operating systems booting on the same computer (a multiboot environment). It is also used on solid-state memory sticks and other similar devices.   FIFO First In, First Out This expression describes the principle of a queue: what comes in first is handled first, what comes in next waits until the first is finished, etc. See also LIFO.   FTP File Transfer Protocol A very common method of moving files between two Internet sites. FTP is a way to login to another Internet site for the purposes of retrieving and/or sending files. This protocol was invented and in wide use long before the advent of the World Wide Web and originally was always used from a text-only interface. G    top top   GB GigaByte A unit of data storage size which represents 2^30 (over 1 billion) characters of information. Please see MB for a detailed description of the byte concept.   GIF Graphic Interchange Format A common format for image files, especially suitable for images containing large areas of the same color. GIF format files of simple images are often smaller than the same file would be if stored in JPEG format, but GIF format does not store photographic images as well as JPEG. GIF files are limited to 256 colors, but allow for animated images.   GIGO Garbage In, Garbage Out A rule stating that the quality of the output is a function of the quality of the input; put garbage in and you get garbage out.   GPS Global Positioning System A constellation of 24 satellites orbiting the earth at a very high altitude. GPS satellites transmit signals that allow one to determine, with great accuracy, the locations of GPS receivers. The receivers can be fixed on the Earth, in moving vehicles, aircraft, or in low-Earth orbiting satellites. GPS is used in air, land and sea navigation, mapping, surveying and other applications where precise positioning is necessary. Implemented by the US Department of Defense.   GSM Global System for Mobile communications Developed in the 1980s, GSM was first deployed in seven European countries in 1992. Originally developed as a pan-European standard for digital mobile telephony, GSM has become the world's most widely used mobile system. It is used on the 900 MHz and 1800 MHz frequencies in Europe, Asia and Australia, and the MHz 1800 frequency in North America and Latin America.   GUI Graphical User Interface A program interface that uses a computer's graphics capabilities to make the program easier to use. Graphical interfaces use a pointing device to select objects, including icons, menus, text boxes, etc. A GUI includes standard formats for representing text and graphics. H    top top   HDSL High-data-rate Digital Subscriber Line See DSL.   HTM(L) Hyper Text Markup (Language) The coding language used to create Hypertext documents for use on the World Wide Web. HTML looks a lot like old-fashioned typesetting code, where you surround a block of text with codes that indicate how it should appear. The "hyper" in Hypertext comes from the fact that in HTML you can specify that a block of text, or an image, is linked to another file on the Internet. HTML files are meant to be viewed using a "Web Browser".  HTML is loosely based on a more comprehensive system for markup called SGML.   HTTP Hyper Text Transfer Protocol An underlying protocol used by the World Wide Web. HTTP defines how messages are formatted and transmitted, and what action Web servers and browsers should take in response to various commands. For example, when you enter a URL in your browser, this actually sends an HTTP command to the Web server directing it to fetch and transmit the requested Web page.   HTTPS Hyper Text Transfer Protocol Secure See HTTP. I    top top   I/O Input/Output Refers to any operation, program, or device whose purpose is to enter data into a computer or to extract data from a computer.   ICT Information and Communication Technology A key phrase to indicate the dynamism that can be achieved with the convergence of computing and telecommunications. Putting the "C" in the middle of the IT is important to emphasise that it is not just about "techie" matters but is relevant to everyone whose job involves communication. ICT makes possible the fast and worldwide exchange of information, and has the capacity to revolutionise work processes, service delivery, etc.   IIS Internet Information Server Microsoft's Web Server, which runs and is only available on Windows NT platforms or later.   IMAP Internet Message (Mail) Application Protocol A standard protocol for accessing e-mail from your local server. IMAP is a client/server protocol in which e-mail is received and held for you by your Internet server. It is different from the standard POP3 method in that with IMAP, e-mail messages are stored on the server, while in POP3, the messages are transfered to the client's computer when they are read. Thus, using IMAP allows you to access your e-mail from more than one machine, while POP3 does not. This is important because some email servers only work with some protocols.   INTERNET INTERnational NETwork A huge worldwide reservoir of information that is made accessible to anyone across the world through the use of computers and high speed interconnected data links. This information may be shared and exchanged publicly or privately. The primary benefit of the Internet lays in its ease in making this information and this vast communication network economically available to virtually everyone (currently estimated at 45 million users). The Internet has only recently began carrying unrestricted commercial traffic. Its initial purpose was to provide a method of rapid information exchange for research, education and defense purposes. The Internet development started in the late 60s & early 70s. Government funding through U.S. Advanced Research Projects Agency created "ARPANET" to develop a communications network for research & military R&D. Truth is: Al Gore did not invent the Internet.   IP Internet Protocol IP specifies the format of packets, also called datagrams, and the addressing scheme. IP by itself is something like the postal system. It allows you to address a package and drop it in the system, but there's no direct link between you and the recipient.   ISAPI Internet Server Application Programming Interface Microsoft's proprietary API for interfacing between the company's Internet Information Server (Web server) and back-end services such as databases. ISAPI can be used in place of the industry standard Common Gateway Interface.   ISDN Integrated Services Digital Network A system of digital phone connections, which allows voice and data to be transmitted simultaneously across the world using end-to-end digital connectivity.   ISO International Standards Organisation Based in Geneva, Switzerland, ISO was founded in 1946. It is an international federation of national standards organizations from over 100 countries. ISO is a word, not an abbreviation, derived from the Greek isos, "equal". It was created in an attempt to avoid creating even more abbreviations for the members' national languages.   ISP Internet Service Provider A company that provides access to the Internet to organizations and/or individuals. J    top top   JPEG Joint Photographic Experts Group Same as JPG.   JPG Joint Photographic Group A standardized image compression mechanism designed for compressing either full-color or grayscale photographic images, often for use on the Web. JPG is "lossy," meaning that the decompressed image is not quite of the same quality as the original image.   JSD Jackson System Development A method of system development that covers the software life cycle either directly or by providing a framework into which more specialized techniques can fit.   JSP 1. JavaServer Pages 2. Jackson Structured Programming 1. Technology that provides a simplified, fast way to create dynamic web content 2. JSD's first method, used to produce the final code. K    top top   Kb Kilobit or Kbit 1024 bits (binary digits). A bit is a single digit number in base-2, either a 1 or a zero, the smallest unit of computerized data. Recall that 8 bits comprise a byte.   kB kiloByte This unit is typically used to measure the size of computer files and other computer applications. A kilobyte is equivalent to 1,024 bytes, and is one of the most common units currently used for measuring electronic data.   Kbps Kilobits per second This unit is typically used to measure bandwidth, or the amount of data that can be transferred in a given amount of time. L    top top   LAN Local Area Network Connects computers in a relatively small area, such as the same floor or building, or a group of buildings like a campus. Users on the same LAN can share devices (such as laser printers, controllers, switches, and gateways) as well as data.   LCD Liquid Crystal Display A flat panel technology which uses liquid crystals sandwiched between two glass plates for example in laptop computers, other small portable displays and also in televisions. LCD displays utilize two sheets of polarizing material with a liquid crystal solution between them. An electric current passed through the liquid causes the crystals to align so that light cannot pass through them. Each crystal, therefore, is like a shutter, either allowing light to pass through or blocking the light. The advantages of LCD screens are: very small power consumption (can be easily battery driven) and low price of mass produced units. Its disadvantages presently include narrow viewing angle, somewhat slower response time, invisibility in the dark unless the display is back-lit, difficulties displaying true colors and resolution limitations.   LIFO Last In, First Out In computer science and queueing theory, LIFO refers to the way items stored in a data structure are processed. The last data to be added to the structure will be the first data to be removed. LIFO mechanisms include data structures such as stacks. See also FIFO.   LPT Line PrinTer The I/O parrallel port that is used to send information to the printer ( and sometimes other parrallel port devices) e.g. LPT:1 LPT:2 etc. M    top top   MB MegaByte 1 Megabyte = 1,048,576 bytes, or 1024 kilobytes (KB). A unit of computer memory, data storage capacity, or data. A megabyte usually refers to 1,000,000 bytes when it's used to describe disk storage capacity and transmission rates. Megabytes are usually used in files that are larger in size, such as mpeg, mpg, avi, asf, and mp3. They are especially used for all movie clips. Megabytes are also used to measure Random Access Memory (RAM) in a computer as well. In fact, Megabytes are the most commonly used form of measurement on most applications for computers, until you measure hard drive space. Almost all newer hard drives measure in Gigabytes (GB), which is 1024 Megabytes.   Mbps Megabits per second A measurement of the transmission speed of data measured in 1,048,576 bits per second.   MD5 Message Digest algorithm 5 A widely-used cryptographic hash function with a 128-bit hash value. As an Internet standard (RFC 1321), MD5 has been employed in a wide variety of security applications, and is also commonly used to check the integrity of files. The algorithm takes as input a message of arbitrary length and produces as output a 128-bit fingerprint or message digest of the input. Any modifications made to the message in transit can then be detected by recalculating the digest. Placed in the public domain by RSA Data Security, Inc. MD5's designer is Ronald Rivest.   Mhz Megahertz This unit is typically used to measure the processor speeds of computers (sometimes referred to as the computer's "clock speed"). One megahertz is one million cycles per second. Every command given to a computer (from the keyboard, mouse, software, hardware, etc.) requires a fixed number of megahertz to execute. The more megahertz available, the faster commands can be executed, and the faster a computer will perform.   MIME Multipurpose Internet Mail Extensions A standard that allows the embedding of arbitrary documents and other binary data of known types (images, sound, video, and so on) into e-mail handled by ordinary Internet electronic mail interchange protocols.   MMS Multimedia Message Service New type of messaging within mobile networks that extends SMS but and actually very much like email. MMS messages can be seen as "slide shows" where each slide consists of text, a picture and an audio object. To support MMS networks will need to integrate new infrastructure elements. End users will need to have mobile phones that support MMS (I.e. have an MMS User Agent). MMS is defined by 3GPP and the WAP Forum.   MODEM MOdulator DEModulator A modem converts digital signals from a computer or other digital device to analog signals (modulates) for transmission over PSTN lines. It converts incoming analog signals back to digital signals (demodulates) for the receiving computer or other digital device. N    top top   NAT Network Address Translation The translation of an Internet Protocol address (IP address) used within one network to a different IP address known within another network. One network is designated the inside network and the other is the outside. Typically, a company maps its local inside network addresses to one or more global outside IP addresses and unmaps the global IP addresses on incoming packets back into local IP addresses. This helps ensure security since each outgoing or incoming request must go through a translation process that also offers the opportunity to qualify or authenticate the request or match it. Consequently, this mechanism also reduces the need for globally unique IP addresses.   NetBEUI NetBIOS Extended User Interface A transport-layer protocol developed by IBM in the mid-1980s, later on provided with Microsoft networking products. NetBEUI is capable of rapid data transfer but is limited to LANs because it is a nonroutable protocol (meaning it does not support routing, which relies on network addresses to move transmissions from one network to another).   NFTS New Technology File System The standard file system of Microsoft Windows NT and its descendants Windows 2000, Windows XP and Windows Server 2003. NTFS replaced Microsoft's previous FAT filesystem, used in MS-DOS and early version of Windows. NTFS has several improvements over FAT such as improved support for metadata and the use of advanced data structures in order to improve performance, reliability and disk space utilization plus additional extensions such as security access control lists and file system journaling.   NNTP Network News Transport Protocol The protocol used by client and server software to carry USENET postings back and forth over a TCP/IP network. If you are using any of the more common software such as Netscape, Nuntius, Internet Explorer, etc. to participate in newsgroups then you are benefiting from an NNTP connection. O    top top   ODBC Open Data Base Connectivity A de facto standard programming interface developed by Microsoft for accessing database data. Because it is a standard applied across DBMS and applications, theoretically, communications between different platforms and DBMSs are transparent using this interface. In fact, some special considerations apply.   ODP Open Directory Project A human edited directory of the web, compiled and maintained by a community of volunteers. It is hosted and administered by Netscape Communication Corporation   OPML Outline Processor Markup Language An XML format for outlines. Originally developed by Radio Userland as a native file format for an outliner application it has since been adopted for other uses, the most common being to exchange list of RSS feeds between RSS aggregators. P    top top   PC Personal Computer Single user computer.   PDF Portable Document Format A file format developed by Adobe Systems for representing documents in a manner that is independent of the original application software, hardware, and operating system used to create those documents. A PDF file can describe documents containing any combination of text, graphics, and images in a device independent and resolution independent format. These documents can be one page or thousands of pages, very simple or extremely complex with a rich use of fonts, graphics, color, and images. PDF is an open standard, and anyone may write applications that can read or write PDFs royalty-free. In addition to encapsulating text and graphics, PDF files are most appropriate for encoding the exact look of a document in a device-independent way. In contrast, markup languages such as HTML defer many display decisions to a rendering device such as a browser, and will not look the same on different computers.   PHP P(ersonal Homepage) Hypertext Preprocessor A widely-used general-purpose scripting language that is especially suited for Web development and can be embedded into HTML   PNG Portable Network Graphics A graphics format designed as the successor to GIF. It features compression, transparency, and progressive loading, like GIF, but it is free of patent restrictions. Supported by most current browsers, beginning in 1997.   POP Post Office Protocol POP3 protocol allows for e-mail to remain on a server until the user is ready to receive it (commonly used by Internet Service Providers). The user downloads their e-mail from the ISP's mail server when they are connected, but the user does not need to be connected in order for mail to be sent to them by other network users. The server holds incoming mail until the user connects and requests his mail.   PSTN Public Switched Telephone Network A voice and data communications service for the general public which uses switched lines. The regular old-fashioned telephone system. Q    top top   Q&A Question and Answer Popular way of treating not always simple issues.   QWERTY QWERTY QWERTY is the modern-day layout of letters on most English language computer and typewriter keyboards. It takes its name from the first six letters shown on the keyboard's top row of letters. The QWERTY design was patented by Christopher Sholes in 1868 and sold to Remington in 1873, when it first appeared in typewriters. The first 6 letters on French-language keyboards are AZERTY. Another common scheme is DVORAK. The Dvorak Simplified Keyboard is a keyboard layout designed by Drs. August Dvorak and William Dealey in the 1920s and 1930s as an alternative to the still-popular QWERTY layout. It has also been called the Simplified Keyboard or American Simplified Keyboard, but is commonly known as the Dvorak keyboard. R    top top   RAM Random Access Memory An integrated circuit memory chip allows information to be stored or accessed in any order and all storage locations are equally accessible. (Parts of) The operating system, application programs, and data in current use are kept here temporarily so that they can be quickly reached by the computer's processor.   RDBMS Relational DataBase Management System Database management system that maintains data records and indices in tables. Relationships may be created and maintained across and among the data and tables.   RDF Resource Description Framework Integrates a variety of applications from library catalogs and world-wide directories to syndication and aggregation of news, software, and content to personal collections of music, photos, and events using XML as an interchange syntax. The RDF specifications provide a lightweight ontology system to support the exchange of knowledge on the Web.   RFC Request For Comments The document series, begun in 1969, which describes the Internet suite of protocols and related experiments. Not all (in fact very few) RFCs describe Internet standards, but all Internet standards are written up as RFCs. The RFC series of documents is unusual in that the proposed protocols are forwarded by the Internet research and development community, acting on their own behalf, as opposed to the formally reviewed and standardized protocols that are promoted by organizations such as CCITT and ANSI. More information on RFC's is here:   http://www.rfc-editor.org/. A complete list of RFCs can be found at   http://www.freesoft.org/CIE/RFC/rfc-ind.cgi.   RGB Red Green Blue Often used in color coding on web pages, particularly for GIF files. 64K color values can be represented by a byte (8 bits of data) each for red, green, and blue. These are commonly expressed in hexadecimal values from 00 too FF for each color. The color value for white in this system is FFFFFF, where each color is at maximum value. Red is FF0000. Yellow is FFFF00. There is a smaller set of non-dithering colors where the permissible values for each color are hexadecimal 00, 33, 66, 99, CC or FF or decimal 0, 51, 102, 153, 204, and 255 and the results will look the same with different browsers, computers, and color cards.   ROM Read Only Memory A semiconductor-based memory system that stores information permanently and does not lose its contents when power is switched off. ROMs are used for firmware, such as the BIOS used in the PC; and in some portable computers, application programs and even the operating system are being stored in ROM.   RPC Remote Procedural Call The concept of executing a function on another process or machine. SOAP is one method of implementing RPC, but it can be used for other purposes.   RPG Report Program Generator One of the first program generators designed for business reports, introduced in 1964 by IBM. In 1970, RPG II added enhancements that made it a mainstay programming language for business applications on IBM's System/3x midrange computers. RPG III and RPG IV added more enhancements and have been widely used on the AS/400. RPGLE added the "Integrated Language Environment (ILE)," which enables C, Java and other modules to be integrated into the program.   RSS Really Simple Syndication A lightweight XML format designed for sharing headlines and other Web content. Think of it as a distributable "What's New" for your site. Originated by UserLand in 1997 and subsequently used by Netscape to fill channels for Netcenter, RSS has evolved into a popular means of sharing content between sites (including the BBC, CNET, CNN, Disney, Forbes, Motley Fool, Wired, Red Herring, Salon, Slashdot, ZDNet, and more). RSS solves myriad problems webmasters commonly face, such as increasing traffic, and gathering and distributing news. RSS can also be the basis for additional content distribution services.   RTF Rich Text Format A method of encoding text formatting and document structure using the ASCII character set. By convention, RTF files have an .rtf file name extension. S    top top   SCSI Small Computer System Interface Pronounced "scuzzy". An interface standard for connecting peripheral devices to computers. Hardware components for implementing a SCSI interface include connector ports on computers and cables for connecting peripheral devices to the computer. SCSI is gradually being supplanted by the newer USB standard.   SDSL Single-line Digital Subscriber Line See DSL.   SGML Standard Generalised Markup Language A standard for how to specify a document markup language or tag set. SGML is not in itself a document language, but a description of how to specify one. It is a metalanguage. HTML and XML are examples of SGML-based languages. As an international standard (ISO 8879) it specifies the rules for the creation of platform-independent markup languages for electronic texts.   SHTM(L) Secure Hyper Text Markup (Language) The file extension for Web pages that contain server side includes (SSIs). This extension however is not a requirement. Servers have to be configured to use this extension or MIME type as a SSI, but once it is the filename extension enables the Web server to differentiate those pages that need to be processed before they are sent to a Web browser.   SIM Subscriber Identity Module a Smart Card installed in every GSM handset. Within the GSM application the three primary roles of the SIM are access control to the network (authentication & ciphering), service personalisation (SMS, advice of charge, etc.), network branding and advertising (graphics printed on SIM card). Any GSM phone becomes immediately programmed after plugging in the SIM card, thus allowing GSM phones to be easily rented or borrowed. SIM cards can be programmed to display custom menus for personalized services. The new generation of Phase 2+ SIMs will enable services such as virtual cash, mobile banking, ticket reservations etc.   SMS Short Message Service A text message service that enables short messages of generally no more than 140-160 characters in length to be sent and transmitted from a cellphone. SMS was introduced in the GSM system and later supported by all other digital-based mobile communications systems. Unlike paging, but similar to e-mail, short messages are stored and forwarded at SMS centers, which means you can retrieve your messages later if you are not immediately available to receive them. SMS messages travel to the cellphone over the system's control channel, which is separate and apart from the voice channel.   SMTP Simple Mail Transfer Protocol SMTP protocol handles e-mail delivery over the network. It handles routing, acceptance and delivery between mail servers. This protocol allows the mail server on the above-mentioned ISP setup to transfer e-mail from their server to another ISP's mailserver, where it is commonly held for delivery to the final destination -- the user who accesses the message through POP3.   SOAP Simple Object Access Protocol An XML-based protocol to allow you to activate an application or object within an application across the Internet.   SPUI Single Page User Interface     SQL Structured Query Language Developed by IBM in the mid-1970s as a way to get information into and out of relational database management systems. A fundamental difference between SQL and standard programming languages is that SQL is declarative. You specify what kind of data you want from the database; the RDBMS is responsible for figuring out how to retrieve it. SQL is a specialized programming language for sending queries to databases. Most industrial-strength and many smaller database applications can be addressed using SQL. Each specific application will have its own version of SQL implementing features unique to that application, but all SQL-capable databases support a common subset of SQL.   SRAM Static Random Access Memory An integrated circuit that retains data in memory as long as power is being supplied. SRAM does not have to be periodically refreshed and provides faster access to data. SRAM PC Cards are powered by batteries which allows for data retention. SRAM typically requires four or six transistors per bit, making it substantially more expensive than DRAM, which usually requires one transistor per bit. SRAM is able to operate at higher speeds and is more reliable than DRAM.   SSI Server Side Includes Aa type of HTML comment. This comment directs the web server to dynamically create data for the web page. They can also be used to execute programs and insert the results of that program to the web page. Pages that have this included usually end with an .shtml extension. Different servers support different commands and there is no official standard.   SSL Secure Sockets Layer A protocol designed by Netscape Communications to enable encrypted, authenticated communications across the Internet. SSL used mostly in communications between web browsers and web servers. URL's that begin with 'https' indicate that an SSL connection will be used. SSL provides 3 important things: Privacy, Authentication and Message Integrity. T    top top   TB TeraByte A unit of data storage size which represents 2^40 (over 1 trillion) characters of information. Please see MB for a detailed description of the byte concept.   TCP Transmission Control Protocol TCP enables two hosts to establish a connection and exchange streams of data. TCP guarantees delivery of data and also guarantees that packets will be delivered in the same order in which they were sent.   TIFF Tag Image File Format A common format for exchanging raster (bitmapped) images between application programs. Usually identified with the ".tiff" or ".tif" filename extension, the format was developed in 1986 by an industry committee chaired by the Aldus Corporation (now part of Adobe). Microsoft and Hewlett-Packard were also on the committee. One of the more common image formats, TIFFs are common in desktop publishing, faxing, and medical imaging applications. TIFF supports black-and-white, gray-scale, pseudocolor, and true-color images, all of which can be stored in a compressed or uncompressed format.   TLD Top Level Domain In the Domain Name System (DNS), the highest level of the hierarchy after the root. In a domain name, that portion of the domain name that appears furthest to the right. Examples of top-level domains include: .COM .NET .ORG .CA .INF .BIZ .US .NAME .CO .UK .TV .CC   TOC Table of Contents The digital subcode information that identifies a disc, indicates the number of tracks, the starting and ending points of these tracks and the total running time of the disc, or a detailed outline of a document that helps reader to grasp and navigate through it and that increases the overall value of information.   TWAIN Technology Without An Interesting Name A protocol for exchanging information between applications and devices such as scanners and digital cameras. TWAIN makes it possible for digital cameras and software to "talk" with one another on PCs. U    top top   UDDI Universal Description, Discovery and Integration A directory model for web services. UDDI is a specification for maintaining standardized directories of information about web services, recording their capabilities, location and requirements in a universally recognized format. Seen (with SOAP and WSDL) as one of the three foundation standards of web services, UDDI is currently the least used of the three.   UDP User Datagram Protocol A communications protocol for the Internet network layer, transport layer, and session layer, which makes it possible to send a datagram message from one computer to an application running in another computer. Like TCP, UDP is used with IP. Unlike TCP, UDP is connectionless and does not guarantee reliable communication; the application itself must process any errors and check for reliable delivery.   UMTS Universal Mobile Telecommunications System A so-called "third-generation (3G)," broadband, packet-based transmission of text, digitized voice, video, and multimedia at data rates up to 2 megabits per second (Mbps) that will offer a consistent set of services to mobile computer and phone users no matter where they are located in the world. Based on the Global System for Mobile (Global System for Mobile communication) communication standard, UMTS, endorsed by major standards bodies and manufacturers, is the planned standard for mobile users around the world.   URC Uniform Resource Characteristic See URN.   URI Uniform Resource Identifier Either a URL or a URN. A URI is a way of identifying content in the web, whether it be a page of text, a video or sound clip, an image, or a program.   URL Uniform Resource Locator The global address of documents and other resources on the World Wide Web. The first part of the address indicates what protocol to use (e.g. http, ftp, etc.), and the second part specifies the IP address or the domain name where the resource is located.   URN Uniform Resource Name The URI architecture requires that a resource be named by a URN and be retrieved by a URL. A URC (Uniform Resource Characteristic) binds the URN of a resource to one or more URLs. Once this system is activated, URNs will be used to "reference" information resources. World Wide Web clients will then send the URN for a desired resource to an international network of URN to URL resolvers (the URC service) that will return to the client one or more URLs that can be used to access the resource. Proposed as a solution to the broken link problem, assuming a location may change, but a name rarely will.   USB Universal Serial Bus An interface standard for connecting peripheral devices to computers. Hardware components for implementing a USB interface include connector ports on computers and cables for connecting peripheral devices, such as a mouse, keyboard, digital camera, printer or scanner, to the computer. The USB standard supports data transfer rates of 12 Mbps. A single USB port can be used to connect up to 127 peripheral devices. USB is gradually replacing SCSI as the dominant peripheral interface standard. Unlike devices connected via SCSI ports, USB devices can be added to and removed from the computer without having to reboot the computer. V    top top   VB Visual Basic A popular Microsoft programming language.   VDSL Very-high-data-rate Digital Subscriber Line See DSL.   VLAN Virtual Local Area Network Group of devices on one or more LANs that are configured (using management software) so that they can communicate as if they were attached to the same wire, when in fact they are located on a number of different LAN segments. Because VLANs are based on logical instead of physical connections, they are extremely flexible. One of the biggest advantages of VLANs is that when a computer is physically moved to another location, it can stay on the same VLAN without any hardware reconfiguration.   VoIP Voice over Internet Protocol A technology for transmitting ordinary telephone calls over the Internet using packetlinked routes. Also called IP telephony.   VPN Virtual Private Network Network scheme in which portions of a network are connected via Internet, but information sent across the Internet is encrypted. The result is a "virtual network" which is also part of a larger network entity. This allows users to privately share private information over a public infrastructure. VPNs are often used to connect offices.   VRAM Video Random Access Memory This type of memory is used on video adapters, and is dual-ported, meaning that it can be accessed by two devices simultaneously. This allows the monitor to access the memory for screen updates, while at the same time allowing the CPU or graphics processor to provide new data. W    top top   WAN Wide Area Network A physical or logical network that provides capabilities for a number of independent devices to communicate with each other over a common transmission-interconnected topology in geographic areas larger than those served by local area networks. Typically, a WAN consists of two or LANs. Technically, the Internet itself is a gigantic, worldwide WAN which is owned by various individuals and corporate or governmental entities.   WAP Wireless Application Protocol The de facto worldwide standard for providing Internet communications and advanced telephony services on digital mobile phones, pagers, personal digital assistants and other wireless terminals. The Wireless Application Protocol is a standard developed by the WAP Forum, a group founded by Nokia, Ericsson, Phone.com (formerly Unwired Planet), and Motorola. WAP defines a communications protocol as well as an application environment. In essence, it is a standardized technology for cross-platform, distributed computing.   WIFI WIreless FIdelity Popular term for a high-frequency wireless local area network (WLAN).   WLAN Wireless Local Area Network Type of local-area network that uses high-frequency radio waves rather than wires to communicate between nodes. WLAN is a flexible data communication system used as an alternative to, or an extension of a wired LAN.   WSDL Web Services Description Language XML document describing a webservice, particularly its location and the way to use it.   WWW World Wide Web Rapidly growing collection of Internet-based servers and clients exchanging documents in hypertext format. The nature of hypertext allows Web clients to "surf" from on on-line document to another with ease. Hypertext documents for Web consumption are requested and then displayed on screen by Web browsing applications. Web servers and browsers all use a common communications protocols such as HTTP.   WYSIWYG What You See Is What You Get. Describes (editing or development) tools that make testing the results of your work very easy. Some show it even while you're developing or changing your file or program. X    top top   XHTML eXtensible Hyper Text Markup Language A hybrid between HTML and XML. Designed for net devices and method of displaying web pages on net and portable devices.   XML eXtensible Markup Language A pared-down version of SSGML, designed especially for Web documents. It allows designers to create their own customised tags, enabling the definition, transmission, validation, and interpretation of data between applications and between organizations. XML is a metalanguage (a way to define tag sets) that allows you to design your own customized markup language for many classes of documents.   XSL eXtensible Style Language A stylesheet language for XML   XSLT eXtensible Style Language Transformation A language for transforming XML documents into other XML documents. XSLT is designed for use as part of XSL. Y    top top   Y2K Year 2000 Often associated with a computer software problem frequently referred to as the Y2K bug, also known as the millennium bug. This refers to the inability of older computer systems to handle dates correctly after the millennium changes. The "Y2K problem" appeared in nearly all software that handles dates and could not distinguish between twentieth century dates that begin with "19" and twenty-first century dates that begin with "00". Most programs represented dates in the form MM-DD-YY, for example, 01-01-00 (instead of 01-01-2000). If the problem was left unresolved, computers could calculate a 100-year reversal instead of a one-day advance on January 1, 2000. It turned into a major fear that critical industries (electricity, financial, etc.) and government functions would stop working at 12:00 AM, January 1, 2000, and at other critical dates which were billed as "event horizons." This fear was fueled by huge amounts of press coverage and speculation, as well as copious official corporate and government reports. All over the world companies and organizations checked and upgraded their computer systems. The preparation for Y2K had a significant effect on the computer industry. In the end, significant disasters such as nuclear reactor meltdowns or plane crashes were avoided, but the number of non-critical Y2K errors encountered on January 1, 2000 was very big. But because of the lack of disasters combined with the "end of the world" expectations the public may have wrongly regarded the Y2K as a non-event. Z    top top   ZIP   A method of compressing a file, making it much smaller in size, and capable of being transferred from one computer to another more quickly. These files are recognized by the ".arc", ".arj", ".b64", ".bhx", ".cab", ".hqx", ".lzh", ".mim", ".tar", ".taz", ".tgz", ".tz", ".uu", ".uue", ".xxe", ".z", and ".zip" extensions. ".zip" is one of the more commonly used types of zipped files.