| ISP Dictionary - ISP Glossary Definitions for 'd' |
| DAC - An electronic device that converts digital signals into analog signals. You can find DACs in a variety of devices, including sound cards. The DAC would... |
| Daemon - A term mainly used regarding UNIX processes. A daemon (or demon) is a process that starts and does nothing until it is called by another process or a certain... |
| Daisy Chain - In computer terminology, this refers to connecting one device (historically SCSI, but now USB or FireWire as well) to another device, instead of directly... |
| Daisy Wheel printer - A printer that uses a wheel with all the characters on it to produce output. The wheel spins to the desired character and makes an imprint, then spins... |
| DAO - This is a single-session method of writing data to a CD-R/RW disc that creates a disc in a format suitable for commercial duplication. Basically, the entire... |
| Dark Fiber - Fiber optic wiring that has been installed but has not been turned on yet. Often, companies that lay fiber optic cabling will lay extra cable, since the... |
| DAT - This type of magnetic tape, introduced by Sony, at one point threatened to supplant the normal audio cassette with a better quality alternative. Unfortunately,... |
| Data - Information. Any series of bits, characters, or objects that has meaning. Data is stored and transmitted by computers. |
| Data Center - Any computing environment where there is a service agreement between the people managing the computing resources and the users. A company computer network... |
| Data Compression - Takes something large and makes it smaller. Compression generally comes in two forms: lossy and lossless. Lossy compression is best used on graphics files... |
| Data Encryption Standard - An encryption method developed by IBM in 1977. It uses a private 56-bit key that is applied to each 64- bit block of data. The sender and receiver must... |
| Data Entry - A job function where the employee is expected to enter data into a computer. Typically, the only technical skill you need for such jobs is typing. Some... |
| data integrity - the assurance that information can only be accessed or modified by those authorized to do so. |
| Data Mining - The act of analyzing a database or data warehouse and searching for new facts based on the data. For example a supermarket may mine its customer data and... |
| Data type - The type of data that is being used in a computer program. Different types of data take up different amounts of space. Some common data types are integer,... |
| Data Warehouse - A large database where information is gathered from various online transaction systems. Usually, this information is put together and "mined," as in datamining,... |
| Data Warehousing - The act of putting data together in a Data Warehouse. |
| database - A collection of data records. On web databases, records may consist of web pages, or graphics, or audio files, or newspaper files, or books, or movies,... |
| DataBase Administrator - A person whose job it is to manage databases. A DBA's tasks may include assigning security privileges to the databases, creating and designing databases,... |
| datagram - In TCP/IP networks, datagram is a synonym for packet. |
| Daughter Board - A circuit board that plugs into a larger circuit board, or motherboard. Often processors are contained on daughterboards, along with cache memory. For... |
| Daughter Card - A circuit board that plugs into a larger circuit board, or motherboard. Often processors are contained on daughterboards, along with cache memory. For... |
| DB-25 - The name for the connector used for parallel ports on PCs. It has 25 pins, as you would expect. |
| DBA - A person whose job it is to manage databases. A DBA's tasks may include assigning security privileges to the databases, creating and designing databases,... |
| DCOM - Yet another Microsoft technology. It is a version of the COM that is designed to work across networks and, specifically, the Internet. |
| DDE - A method of exchanging data between applications on MacOS, Windows, and OS/2 operating systems. DDE is similar to OLE, but predates it. It enables multiple... |
| DDR II SDRAM - A standard that is used to boost conventional SDRAM memory up to speeds of 200MHz and beyond.Standard SDRAM tops out around 150-166MHz, and DDR SDRAM starts... |
| DDR SDRAM - A standard that is used to boost conventional SDRAM memory up to speeds of 200MHz and beyond.Standard SDRAM tops out around 150-166MHz, and DDR SDRAM starts... |
| DDS - A storage standard used with medium cost tape media and tape drives, used mainly for small businesses and departmental backups. DDS tapes are the same... |
| Debug - The act of diagnosing, fixing, or removing bugs from a computer programs. It can also be used to describe the fixing of bugs in HTML or other computer-based... |
| Debugger - A program that searches other programs for bugs. In addition to identifying definite or possible bugs, debuggers can usually step through programs one... |
| Decibel - A logarithmic measure of sound intensity. It is equal to 10 times the common logarithm of the ratio of sound intensity to a reference intensity. A rating... |
| Decrypt - The act of decoding data that has been encrypted. |
| Decryption - The act of decoding encrypted data so that it can be understood. |
| DeCSS - A program that was developed to allow Linux to read DVD movies scrambled with the Content Scrambling System. The writers of the program reverse engineered... |
| Dedicated Line - Often used to mean a telephone line used solely for your computer modem or fax machine, and not used for voice calls--although it technically could be.... |
| Default - The fallback value. If nothing else is specified the default value will be used. If you install a program it generally installs with the default settings... |
| Defrag - Slang for the act of defragmenting a hard drive. When you defragment a hard drive you use a software utility to arrange the order of your files so that... |
| Defragment - When you defragment a hard drive you use a software utility to arrange the order of your files so that each file is represented in a physically continuous... |
| Degauss - The act of de-magnetizing a CRT monitor or magnetic media. Degaussing a CRT monitor is necessary when a monitor has been moved in relation to the Earth's... |
| Delimited - The separation of data elements in a text file by a character or combination of characters. The character that separates the elements is the delimiter.... |
| DeMilitarized Zone - A part of a network that is protected by a firewall, but may be accessed by external Internet clients. The DMZ generally contains servers such as SMTP... |
| Demon - A term mainly used regarding UNIX processes. A daemon (or demon) is a process that starts and does nothing until it is called by another process or a certain... |
| Demultiplexer - A logic circuit that takes a single input and sends it to one of several outputs. In networking, it is used to describe a device that receives a transmission... |
| Demux - A logic circuit that takes a single input and sends it to one of several outputs. In networking, it is used to describe a device that receives a transmission... |
| Denial of Service - A type of network attack that attempts to render a network or Internet resource useless to users, typically by sending large amounts of repeated requests... |
| DES - An encryption method developed by IBM in 1977. It uses a private 56-bit key that is applied to each 64- bit block of data. The sender and receiver must... |
| Desktop Case - A computer case designed to sit on your desktop. It's wider than it is tall and sturdy enough to put a heavy CRT monitor on top of it. |
| Desktop Management Interface - A system that allows computers to send distress signals to a main system on a network. It is a means to detect problems before they crash the computer... |
| Desktop Management Task Force - This motley crew was assembled to create the DMI standard. |
| Develop - A synonym for programming. It describes the act of creating a computer program. |
| Developer - A person who creates computer programs, and may specialize in one or more methods of creating computer programs, Web pages, or programming languages, such... |
| Device Bay Interface Specification - A specification originally designed to provide a simple and generic way of interfacing computers and their components.Device Bay devices are about the... |
| Device Driver - This is basically synonymous with the term "driver." It's a piece of software that tells an operating system specifically how to communicate with a device.... |
| DFS - A Microsoft technology introduced in Windows 2000 that allows multiple servers and shared directories on a network to appear as a single network drive,... |
| DHCP - A method of automatically assigning a TCP/IP address to a client. A DHCP server is used to dole out a TCP/IP address from a pool of TCP/IP addresses to... |
| DHTML - This was independently defined by Microsoft and Netscape and implemented in version 4 of their browsers to allow for more dynamic and user-interactive... |
| Diagnostics - A procedure or program that is run internally to test a piece of software or hardware and ensure that it is operating properly. For example, if R2-D2 of... |
| Diamondtron - This is Mitsubishi's answer to Sony's Trinitron. Instead of rectangular pixels, Diamondtron used diamond- shaped ones which supposedly offer crisper text.... |
| DIB - The bus architecture between Intel's Pentium II processor, memory, and L2 cache. One bus connects the processor to L2 cache and a second connects the processor... |
| Die size - Simply put, this is the two dimensional (length by width) measurement of a microprocessor. The thickness of the processor is not considered. Typical die... |
| Differential SCSI - This type of SCSI is used to connect devices that are far apart or that may suffer from interference. Standard SCSI cabling is limited to 6 meters; differential... |
| differentiated services - At present, all packets on the Internet are treated alike, regardless of their importance. If you want an important message to be delivered immediately... |
| Digital - This implies a value represented by a group of discrete steps. Some claim that digital representations of images and sound are more accurate; others that... |
| Digital Audio Tape - This type of magnetic tape, introduced by Sony, at one point threatened to supplant the normal audio cassette with a better quality alternative. Unfortunately,... |
| Digital Control - A control that doesn't directly cause a physical change in something, but rather sends a signal that a processor interprets. The processor then makes the... |
| Digital Data Storage - A storage standard used with medium cost tape media and tape drives, used mainly for small businesses and departmental backups. DDS tapes are the same... |
| Digital Linear Tape - A technology designed by DEC and sold to Quantum used for backing up huge amounts of data (up to 35 GB per tape without compression, 70 GB with compression).... |
| Digital Millennium Copyright Act - A controversial reform of the U.S. copyright laws that is the first attempt to update those laws for the age of digital technology. It covers circumvention... |
| Digital Nervous System (DNS) - A term used by Bill Gates in frequent speeches in 1997 and 2000. Gates describes a future merging of PCs and communications in a wireless networked environment... |
| Digital Signal level 0 - The signal used to carry a standard analog or digital phone line connection. 24 DS-0 connections can be carried on a T1 line. The speed of the line is... |
| Digital Signal level 1 - Synonym for T1. |
| Digital Signal level 2 - Synonym for T2 |
| Digital Signal level 3 - Synonym for T3. |
| Digital Signal level 4 - Synonym for T4. |
| Digital Signal level 5 - Synonym for T5 |
| Digital Signal Processor - A DSP is a microprocessor designed to work with analog signals such as video or audio that have been digitally encoded. The DSP then takes these digital... |
| Digital signature - A form of electronic signature that works with a public and private key encryption system and a certificate authority. To sign an electronic document with... |
| Digital Subscriber Line - A form of high-speed Internet access currently competing with cable modems. DSL works over standard copper phone lines. In fact, most DSL service is limited... |
| Digital Television - Standard television signals are in analog format. Some HDTV systems (such as Japan's early efforts) use analog signals as well. Digital Television refers... |
| Digital to Analog Convertor - An electronic device that converts digital signals into analog signals. You can find DACs in a variety of devices, including sound cards. The DAC would... |
| Digital Variable/Versatile/Video Disc - This is much like a CD-ROM except that it stores over 7 times as much data in its simplest form. DVD is the successor to CD-ROM technology. DVD discs are... |
| Digital Video Interface - A connection standard for linking a video card and a display that requires a digital signal, such as an LCD panel. Analog video signals can also be used... |
| Dill - The abbreviated way to say "DLL," which is a Windows file extension that stands for dynamic link library. |
| DIMM - A circuit board with memory chips on it, very much like a SIMM except that it is larger and contains more pins. DIMMs are 64-bit memory devices, so you... |
| Diode - An electronic device with two electrodes/terminals, one called the cathode and the other the anode, and a single PN junction (which uses part P-type and... |
| Dip Switch - One or more switches that are housed in a rectangular box on a circuit board. The switches are binary in nature, either on or off for each switch. Dip... |
| Direct Current - A type of electrical current that moves in one direction at a constant rate, such as a standard 9 volt battery. Batteries provide direct current. See also... |
| Direct Memory Access - PCs have DMA channels that allow certain devices to directly access memory to speed up the process. In addition to IRQ settings, you used to have to worry... |
| Direct Rambus DRAM - One possible future successor to SDRAM, and competitor to DDR SDRAM. DRDRAM (also now simply called RDRAM) was originally developed by Rambus, Inc. This... |
| DirectDraw - A set of APIs introduced for Windows 95 and NT that allow programmers to directly access the video controller, allowing for faster graphics response. |
| Directory - The name for a logical container for files. Directories were devised to organize files. Without directories, all the files on your hard drive would be... |
| DirectX - A Microsoft technology that first worked under Windows 95 and Windows NT 4.x. Basically, it's a set of APIs that allow programmers to access more directly... |
| Disc at Once - This is a single-session method of writing data to a CD-R/RW disc that creates a disc in a format suitable for commercial duplication. Basically, the entire... |
| Disk Drive - Often, this is a synonym for hard drive, but it can also refer to a floppy drive or any type of removable drive that uses magnetic media. |
| Disk Duplexing - There are two forms of RAID 1: disk duplexing and disk mirroring. Disk mirroring involves two hard drives that are on the same drive controller. The same... |
| Disk Mirroring - There are two forms of RAID 1: disk duplexing and disk mirroring. Disk mirroring involves two hard drives that are on the same drive controller. The same... |
| Disk Operating System - This OS is what got it all started for PCs. It was produced by Microsoft and was a 16-bit command line (non-GUI) operating system, designed to run on 16-bit... |
| Disk Striping - Also known as disk striping, this form of RAID combines two or more hard drives into a single logical drive. Any data is written in blocks first to one... |
| Disk Striping with Parity - A RAID 5 configuration utilizes three or more hard drives and stripes the data across them, much like RAID 0. The difference is that parity information... |
| Diskette - This term is synonymous with floppy disk. You may also hear the long version, floppy diskette. Nowadays most people just say "disk." |
| Distributed Component Object Model - Yet another Microsoft technology. It is a version of the COM that is designed to work across networks and, specifically, the Internet. |
| Distributed File System - A Microsoft technology introduced in Windows 2000 that allows multiple servers and shared directories on a network to appear as a single network drive,... |
| dither - To simulate a color that is not part of the current palette on-screen (or in print) by combining pixels of different colors close to each other. Viewed... |
| Divx - This was supposed to be a standard that would offer competition to DVD movies, and allow people to purchase Divx discs that would only be enabled for a... |
| DjVu - Pronounced "deja vu". It is a compressed graphics format for showing scanned pages on the web. It does for scanned pages what PDF format does for electronically... |
| DLL - A library of procedures that programs can call on. The DLL produces output related to the supplied input. DLLs can be somewhat of a black box, as you don't... |
| DLP Projector - A display device that can project an image onto a wall or projection screen. This type of projector competes with LCD projectors, and instead of tiny embedded... |
| DLT - A technology designed by DEC and sold to Quantum used for backing up huge amounts of data (up to 35 GB per tape without compression, 70 GB with compression).... |
| DMA - PCs have DMA channels that allow certain devices to directly access memory to speed up the process. In addition to IRQ settings, you used to have to worry... |
| DMCA - A controversial reform of the U.S. copyright laws that is the first attempt to update those laws for the age of digital technology. It covers circumvention... |
| DMI - A system that allows computers to send distress signals to a main system on a network. It is a means to detect problems before they crash the computer... |
| DMI Pool - The set of data about a computer and its components, including partition data for your hard drive. When a PC boots it will display the message, "Verifying... |
| DMTF - This motley crew was assembled to create the DMI standard. |
| DMZ - A part of a network that is protected by a firewall, but may be accessed by external Internet clients. The DMZ generally contains servers such as SMTP... |
| DNS - This service maps TCP/IP numbers, such as 123.12.4.245, to a more easily remembered name, such as www.geek.com. Thus, when you type www.geek.com into your... |
| DNS Entry - The DNS routing tables are filled with DNS entries that map TCP/IP addresses to more easily recognized names. If your browser says it can't find a particular... |
| Docking Station - A device into which a laptop connects to gain functionality it has sacrificed for portability. Most laptops have a proprietary connector on the back. Many... |
| DOCSIS - This is a standard for cable modems that was ratified by the ITU in March 1998. Before DOCSIS, cable modems made by one brand would not necessarily work... |
| Domain - This term describes the Internet's addressing scheme, and also a security construct in Windows operating systems. For the Internet, domains are represented... |
| domain name - Domain name addresses, together with IP |
| Domain Name Service - This service maps TCP/IP numbers, such as 123.12.4.245, to a more easily remembered name, such as www.geek.com. Thus, when you type www.geek.com into your... |
| Domain Name System (DNS) - Domain Name System. DNS servers are located at many strategic places on the nets to resolve the routing of e-mail and Internet connections. There are thirteen... |
| Dongle - The slang term for an external hardware device with some memory inside it that attaches to your computer and dangles off of it (thus the term dongle).... |
| dOoDz - Pronounced "dudes." Immature scofflaws. See wareZ |
| DOS - see Disk Operating System or Denial of Service |
| DoS (See also DOS, preceeding) - Acronym of Denial of Service, a form of assault on an Internet site which floods the site with packets requiring a response, thus slowing down or preventing... |
| DOS (See also DoS, which follows) - Acronym for Disk Operating System. Literally, the term refers that portion of an operating system that controls writing, storage, and retrieval of data... |
| Dot Bomb - This is a derogatory slang term for the era of the Dot Com website when many companies were funded with unrealistic expectations and questionable business... |
| Dot Com - This literally refers to the suffix of a domain name intended to be used for websites associated with companies. Figuratively, "Dot Com" is used often... |
| Dot Matrix Printer - This type of printer prints out little dots that can form graphics or characters. It was popular a while back because the only other choice was a daisy-... |
| Dot Pitch - The smaller the better, as it relates to CRT monitors. The dot pitch is a measure of distance between phosphor dots of the same color on a CRT monitor.... |
| Dots Per Inch - Most often this term is used to describe printer or scanner resolution. If a printer is said to print at 300 dpi, it will be capable of printing 300 dots... |
| Double Buffering - A method of smoothing onscreen animation using two buffers to hold images. By rendering both images offscreen, the computer can then display a smoother... |
| Double Data Rate SDRAM - A standard that is used to boost conventional SDRAM memory up to speeds of 200MHz and beyond.Standard SDRAM tops out around 150-166MHz, and DDR SDRAM starts... |
| Double-layer SuperTwist Nematic - This is a form of passive matrix LCD screen. It is an improved version of the standard supertwist nematic passive matrix LCD screen where the display is... |
| download - To transfer a file from another system to your own computer system via a modem over telephone or cable lines or a telnet connection using a transfer protocol... |
| Downstream - The downloading (receiving) of data from the Internet to a client machine. Downstream speeds are typically much greater than upstream speeds in high speed... |
| DPI - Most often this term is used to describe printer or scanner resolution. If a printer is said to print at 300 dpi, it will be capable of printing 300 dots... |
| DPMA - This architecture allows computers to have a variety of advanced power management features. |
| DQYDJ - Chat slang shorthand for "Don't quit your day job!" |
| Dr. Watson - This is diagnostic software that runs automatically in Windows NT/2000/XP and can be turned on in Windows98/Me. Dr. Watson takes over when a program crashes... |
| DRAM - This is the most common form of computer memory. It needs to be continually refreshed in order to properly hold data, thus the term "dynamic." If the power... |
| DRDRAM - One possible future successor to SDRAM, and competitor to DDR SDRAM. DRDRAM (also now simply called RDRAM) was originally developed by Rambus, Inc. This... |
| Drive Bay - This is usually a 5.25" wide 1" tall hole in a computer case suitable for the installation of some sort of drive. Some are exposed so that a removable... |
| drive-by download - a download that occurs without user knowledge or consent. Can occur as the result of visiting a specific Web site or by clicking a deceptive button on... |
| Driver - A driver is software that works to communicate between an operating system and a peripheral. Think of it as a translator. If you use a crappy driver, your... |
| Dropdown Menu - A type of menu that appears as a text box with an arrow pointing down in part of the box. It allows a user to click on it, and a list of choices appear... |
| Drum - The part of a laser printer onto which the laser produces an electrostatic image. The drum is then rolled in toner and that toner is transferred to paper... |
| DS-0 - The signal used to carry a standard analog or digital phone line connection. 24 DS-0 connections can be carried on a T1 line. The speed of the line is... |
| DS-1 - Synonym for T1. |
| DS-2 - Synonym for T2. |
| DS-3 - Synonym for T3. |
| DS-4 - Synonym for T4. |
| DS-5 - Synonym for T5. |
| DSL - Acronym for Digital Subscriber Line or Digital Subscriber Loop, often referred to as xDSL. It refers to several new digital technologies for fast two-way... |
| DSP - A DSP is a microprocessor designed to work with analog signals such as video or audio that have been digitally encoded. The DSP then takes these digital... |
| DSTN - This is a form of passive matrix LCD screen. It is an improved version of the standard supertwist nematic passive matrix LCD screen where the display is... |
| DSU/CSU - A piece of hardware that you use to translate the digital data frames of a T1 line into a 10BaseT connection where Internet connectivity is concerned.... |
| DTD - Acronym for Document Type Definition or optionally Document Type Declaration, used in SGML and XML markup languages to specify the set of rules or grammar... |
| DTS Digital Surround - A form of encoding and decoding surround sound first used in 1993 in the film Jurassic Park. It features 6 discrete channels of audio, with 5 standard... |
| DTV - Standard television signals are in analog format. Some HDTV systems (such as Japan's early efforts) use analog signals as well. Digital Television refers... |
| Dual boot - A system that can boot to two different operating systems. Some OSes, such as Windows NT/2000/XP and versions of Linux, allow for dual booting when installed.... |
| Dual Homed - This refers to a computer with two network cards. Such configurations are often used to function as routers in a situation where two networks are connected... |
| Dual In-Line Memory Module - A circuit board with memory chips on it, very much like a SIMM except that it is larger and contains more pins. DIMMs are 64-bit memory devices, so you... |
| Dual Independent Bus - The bus architecture between Intel's Pentium II processor, memory, and L2 cache. One bus connects the processor to L2 cache and a second connects the processor... |
| Dualscan - A passive matrix LCD screen that uses a better method of displaying graphics, producing a sharper, more vivid image than standard passive matrix screens.... |
| Dublin Core - A proposed set of standard descriptive metadata elements used with web resources to aid in resource discovery. The elements are intended as a starting... |
| Dumb Terminal - These are hooked up to mainframes, and are little more than a monitor attached to a keyboard. All they are good for is running programs using the mainframe's... |
| Duplex - A telecommunications term that describes part of the communications between a local modem and a remote computer. In full duplex mode, the remote computer... |
| DVD - This is much like a CD-ROM except that it stores over 7 times as much data in its simplest form. DVD is the successor to CD-ROM technology. DVD discs are... |
| DVD+R - This standard writes to DVD+R media and is write once read many (WORM). It is being pushed by HP, Dell, and others as the next de facto DVD writing standard,... |
| DVD+RW - This standard reads standard DVD-ROM discs, and reads and writes to DVD+RW media. |
| DVD-R - This standard is to DVD-ROM like CD-R is to CD-ROM. It uses 4.7 GB disks that can only be written to once, and which then can be read by standard DVD-ROM... |
| DVD-RAM - The DVD-RAM standard uses media that can be written and read multiple times, like RAM chips. The first DVD-RAM media held 2.6 GB worth of data per side,... |
| DVD-RW - The rewriteable form of DVD-R. It is being added on to some DVD-R drives to add functionality. DVD-RW disks can write 4.7 GB of data. |
| DVI - A connection standard for linking a video card and a display that requires a digital signal, such as an LCD panel. Analog video signals can also be used... |
| Dynamic Data Exchange - A method of exchanging data between applications on MacOS, Windows, and OS/2 operating systems. DDE is similar to OLE, but predates it. It enables multiple... |
| Dynamic Host Configuration Protocol - A method of automatically assigning a TCP/IP address to a client. A DHCP server is used to dole out a TCP/IP address from a pool of TCP/IP addresses to... |
| Dynamic HTML - This was independently defined by Microsoft and Netscape and implemented in version 4 of their browsers to allow for more dynamic and user-interactive... |
| Dynamic HTML (DHTML) - A more powerful model for HTML that allows absolute control of positioning of elements on a page and more powerful control of events. It is supported by... |
| Dynamic Link Library - A library of procedures that programs can call on. The DLL produces output related to the supplied input. DLLs can be somewhat of a black box, as you don't... |
| Dynamic Power Management Architecture - This architecture allows computers to have a variety of advanced power management features. |
| Dynamic Random Access Memory - This is the most common form of computer memory. It needs to be continually refreshed in order to properly hold data, thus the term "dynamic." If the power... |
