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• Daemon:
  This refers to a program that is designed to run continuously in the background and is activated by a particular event. Examples of Daemons are: mail server daemons, web server daemons or printer daemons.
   

• Daisy Chain:
  A hardware configuration in which devices are connected one to another in a series. The SCSI interface , for example, supports a daisy chain of up to 7 devices.
   

• Data: 
  This refers to the information that is stored on a computer system.
   

• Database: 
  Anything that accepts data is a database. A pile of newspapers is a database. A computer database has the ability to manipulate that data. It is possible to attach applications to that database to search the contents.
   

• Data Bus:
  Data Buses are used on a systems motherboard and contain a group of parallel conductors also known as circuit traces. Data Buses are used by the CPU to transmit and receive data from all connected devices in a computer system. It is also referred to as the external data bus.
   

• Data Communications:
  The moving or sharing of encoded information between two or more data sources using an electronic medium.
   

• Data Conversion:
  Refers to translating data from one format to another. It is most commonly used to reformat data that is being transferred from one system to another so that the receiving system can interpret the information correctly.
   

• Data mining:
  Sorting through data to identify patterns and establish relationships. Data mining parameters include: 
  
  -Association - looking for patterns where one event is connected to another event.
  -Sequence or path analysis - looking for patterns where one event leads to another later event. 
  -Classification - looking for new patterns (May result in a change in the way the data is organized but that's ok). 
  -Clustering - finding and visually documenting groups of facts not previously known. 
  -Forecasting - discovering patterns in data that can lead to reasonable predictions about the future.
   

• Data Rate: 
  A speed measurement that calculates how fast information is moved from one place to another. This is usually measured in bits.
   

• Data Striping:
  A method of separating data from one disk drive and distributing it across several hard disks. The benefits of Data Striping are:
  
  -When a processor is capable of reading or writing faster than a single disk drive can accept the information. Data Striping will increase the I/O performance.
  -Gives the ability to create larger logical volumes.
  -Reduces the possibility of disk drive failure.
   

• Daughter Card:
  Often called Daughter Board. it is a printed circuit board that plugs into another circuit board (usually the motherboard). A daughter card is similar to an expansion board, but it accesses the motherboard components (memory and CPU) directly instead of sending data through the slower expansion bus. It is different from other expansion boards in the system due to it often having pins, plugs, sockets or connectors.
   

• DDR:
  Stands for "Double Data Rate." A type of advanced SDRAM designed to deliver data at a double rate of speed for a given clock frequency. DDR is used in some of the newer video cards such as Nvidia GeForce.
   

• DDS: 
  Stands for Direct Digital Signal. It refers to a network that uses digital infrastructure equipment exclusively. This eliminates the need for analog-to-digital converters on a network because all signals are transmitted digitally. 
   

• DECnet:
  A proprietary set of networking protocols developed by the Digital Equipment Corporation. It was the first peer-to-peer networking architectures to emerge in the 1980's.
   

• Decoder:
  A software, hardware or circuit that is designed to translate a coded or scrambled signal in to a readable form. A common use for this is by cable companies that scramble a signal until a subscriber becomes authorized to view the signal. The cable company then decodes the signal in to a viewable form. 
   

• Decryption:
  This is a process of converting information in to a readable form that has been encrypted by the use of an encryption algorithm. A common use could be that a person would like to protect sensitive data that resides on their computer system, so they would use an encryption software to scramble the information. The same software that scrambles the information would be the only authorized entity to decrypt the information. This software could be made available to any authorized person for decryption purposes at other locations.
   

• Dedicated Line: 
  This refers to a phone line that is a phone line that is connected for one purpose. Many computer users use a dedicated line specifically for their computer system.
   

• Degauss:
  To remove magnetism from a device. The term is usually used in reference to color monitors and other display devices that use a Cathode Ray Tube (CRT). These devices aim electrons onto the display screen by creating magnetic fields inside the CRT. External magnetic forces -- such as the earth's natural magnetism or a magnet placed close to the monitor -- can magnetize the shadow mask, causing distorted images and colors. To remove this external magnetic forces, most monitors automatically degauss the CRT whenever you turn on the monitor. In addition, many monitors have a manual degauss button that performs a more thorough degaussing of the CRT. You can also use an external degausser that degausses the monitor from the outside. Since it may be impossible to remove the external magnetic force, degaussing works by re-aligning the magnetic fields inside the CRT to compensate for the external magnetism.
   

• Delimiter:
  A text character that marks the beginning and/or end of a unit of data or separates different data components. For example, periods are used as delimiters in domain names, hyphens and parentheses are used in phone numbers and social security numbers, and blank spaces and commas are used in written text. In HTML the opening delimiter of an element or tag is the less than symbol, <, and the closing delimiter is greater than symbol, >. 
   

• Demodulation: 
  This is a process used by some phone companies that convert an analog signal in to digital signal for use by computer systems.
   

• Desktop:
  Once an operating system finishes loading and you are able to see the graphical background and program icons, this is said to be your "desktop". The electronic desktop is a metaphor for the actual desktop at your home or office in which you will find your many business tools.
   

• Desktop Window Manager (DWM):
  This new visual style (Aero Glass) and look in Windows Vista is powered by Windows Vista's Desktop Window Manager. A video card supporting the Longhorn Display Driver Model (LDDM) system is necessary to view Aero Glass.
   

• DHCP:
  Dynamic Host Configuration Protocol. This is a process of dynamically allocating IP addresses so that they can be reused. This provides a way of managing IP addresses for all PC's connected to cable modems in a network.
   

• DHTML: 
  Stands for Dynamic HTML. This term applies to many web design standards such as HTML, JavaScript and CSS where these elements may be intermixed to create more dynamic design elements. By using DHTML, users can have the ability to drag or click preset design features of a web page.
   

• Dial-Up Line: 
  This is a telephone line that is connected to a server. When it is called, tones are exchanged between the server and the devise calling in order to attach.
   

• Dial-Up Networking:
  This is a feature that was used by the Windows 95, 98 and Unix operating systems. It allows for the connection of other computer systems over the Internet using a phone line connected to a modem.
   

• Digital: 
  A system that defines data in a discrete, non-fluctuating (i.e., non-analogue), numerical method. Similar to a binary system.
   

• Digital Light Processing (DLP):
  A video projection technology that uses hundreds of thousands of rotating mirrors to project high quality, high definition images. DLP was originally developed by Texas Instruments.
   

• DIMM:
  Short for Dual In-line Memory Module. DIMM is a later version of memory than that of its earlier SIMM (Single In-line) counterpart. A DIMM module was introduced for the Pentium processor because the Pentium processor needed a 64 bit path. The SIMM module only has a 32 bit path. Also, SIMM modules are required to be replaced in pair whereas the DIMM modules can be replaced one at a time. 
   

• DIP:
  Acronym for Dual In-line Package. This is a type of chip that was most popular when memory was directly installed on the motherboard. It can be identified by its rectangular casing and has two rows of connector pins on both sides.
   

• Direct X:
  Developed by Microsoft for its Windows operating systems. This technology was designed to provide a much broader gaming or multimedia environment. In the later versions of DirectX, more attention to 3D graphics have been applied. It works by giving software developers direct access to low-level functions of a PC's peripherals by providing a set of application programming interfaces (APIs).
   

• Directory:
  In computing, this refers to the separate entities of a file system. A directory can contain thousands of files and folders used as a means of adding or updating data and is usually an organized searchable reference.
   

• Distributed Network:
  A network using multiple locations. This process if very effective when a specific job can be dynamically tackled by each node in the network rather than by using one individual machines processor.
   

• DLL:
  Dynamic Link Library. This refers to a file that contains executable code that can be used by many different programs at the same time. DLLs have great benefits to a systems storage structure and offer performance benefits as well. Once a program is activated, the DLL file for that program is executed giving the system the proper instruction for that program. If another program uses the same set of instructions, the same DLL will will execute the same instructions for that program. Having the DLL files saves the system from storing this information in a dedicated manor which creates a faster load time for the program and saves a lot of space on a systems hard drive. Dynamic link libraries are stored in files with the .DLL file extension. 
   

• DMA:
  (Direct Memory Access) This is a method of bypassing the central processing unit (CPU) and handling data transfers between the memory and peripheral devices. Systems having DMA channels can transfer data much more quickly than those without.
   

• DNS: 
  Domain Name Service. This service changes alphabetical domain names in to IP (Internet protocol) addresses. While domain names, such as 5StarSupport are very easy to remember, the Internet is made up of IP addresses. Here's how it works; a company or organization settles on a domain name to use. They then purchase the unique name from a DNS server. The organization then purchases a hosting package from an Internet hosting service. The organization can now upload all of their web site information to the host using a special code supplied by the DNS server.
   

• DOCSIS:
  Data Over Cable Service Interface Specification. This is a cable modem standard that was developed by CableLabs. It handles the incoming and outgoing data signals between cable TV networks, personal computers or television sets.
   

• Dongle:
  A device that attaches to a computer to control access to a particular application. Dongles provide the most effective means of copy protection. Typically, the dongle attaches to a PC's parallel port. On Macintoshes, the dongle sometimes attaches to the ADB port. The dongle passes through all data coming through the port so it does not prevent the port from being used for other purposes. In fact, it's possible to attach several dongles to the same port.
   

• DOS: 
  Stands for Disc Operating System. This is a command line operating system that was created by Bill Gates while he was working for IBM. The Windows operating systems are designed to run on top of the DOS system. It is more commonly referred to as MS-DOS. The MS stands for Microsoft.
   

• Downstream:
  This term refers to any information that is being received by a computer system. If the information is leaving the computer system it is referred to as "upstream".
   

• Downstream frequency:
  Refers to the frequency that is used when transmitting information between the CMTS and cable modem.
   

• Domain:
  A domain is a computer, web site or network that is connected to the Internet. A typical domain name looks like this: www.5starsupport.com. The "www" prefix signifies that it is connected to the world wide web. The "5starsupport" or body usually indicates the company name and the suffix "com" is the indicates that it is a commercial site.
   

• Domain Name:
  This is a unique identifier of an organization attached to the Internet. Domain names are used to make a web site easier to remember rather than trying to remember a series of long numbers known as an IP (Internet Protocol) address. 
   

• Dot Pitch:
  An image measurement taken from center to center between stripes or phosphor dots on monitor. The smaller the number, the better the image quality. This measurement is taken in millimeters and it is considered that 0.28 mm is the minimum acceptable display quality. The dot pitch of color monitors for personal computers ranges from about 0.15 mm to 0.30 mm. Other terms for dot pitch is phosphor pitch or line pitch.
   

• DPI: 
  Stands for Dots Per Inch. An image measurement standard that measures an images resolution as it applies to printers. It measures the images pixels in one square inch. The higher the number the better the images resolution or quality. A typical laser jet printers produce a resolution of about 300dpi. Photo quality inkjet printers produce a resolution ranging from 1200 to 2400 dpi.
   

• DRAM:
  Dynamic Random Access Memory. This is a common type of random access memory that is used in personal computing. The "dynamic" in its name is due to the fact that this memory needs to be refreshed as opposed to other SRAM that is "static". The DRAM is refreshed by the use of electrical current pulses that pass through all memory cells. DRAM needs to be periodically refreshed to retain the stored data.
   

• Drive Bay:
  An allocated space inside a computer case where an internal device such as a; floppy, CD-ROM or DVD-ROM is mounted.
   

• Driver:
  A driver is a software program that is the driving force behind a device. Each computer device needs a driver. Many drivers are included with a computers operating system when you purchase it such as; keyboard, monitor and disk drives. In a Windows operating system, the divers file extension is .DRV. In a DOS system, they are .SYS. The driver is written with specific commands for the device it is written for.
   

• DSP:
  Digital Signal Processor. DSP is a technology that is commonly used in devices such as sound cards, fax machines, cellular phones, modems, high-capacity hard disk drives and televisions. DSP chips process large amounts of digital information very quickly. Because of its quick processing abilities, this technology continues to grow fast to meet the needs of today's wireless and multimedia markets.
   

• DTP:
  Desk Top Publisher (ing) - A PC Term that describes a program that enables you to design, create and print a variety of projects such as letterheads, birthday cards, calendars, business cards, invitations etc. that would have previously only been possible by using the services of an outside printers business. 
   

• Dual Core:
  This refers to a new Central Processing Unit (CPU) structure. The difference between a single core and dual core is that a dual core system has two CPU's that are electronically wired together. These two CPU's wired together in parallel gives twice the performance than that of its single core counterpart.
   

• Dumb Terminal: 
  This refers to a monitor a keyboard setup that can receive, enter, transmit and display information from a server. But it cannot process any information. Most commonly, these terminals were used to communicate with another computer over a network. Dumb terminals are a thing of the past due to today's availability of cheap computers.
   

• Duplex:
  This refers to a communication channel that has the ability to transmit in both directions. This is widely used in printing as you can print on both sides of the paper at once. Sometimes referred to as Full Duplex.
   

• DVD:
  Digital Versatile Disc or Digital Video Disc. This popular technology was first introduced in 1996. Its ability to store large amounts of information reliably made this a very common optical disc storage technology. It can hold between 4 to 28 times more data than that of the CD. A single sided DVD can store 4.7 GB (gigabytes) of information and 8.5 GB on dual-layered discs. Double sided DVDs can handle 9.4 GB on a single layered disc and 17 GB on a dual layered disc.
   

• Dynamic Programming Language:
  This dynamic programming language has the ability to change the program structure as it runs.
   

• Dynamic URL: 
  A Web site that is database driven can produce dynamic URLs. Or a URL of a Web site that is produced by running a script can be considered to be a dynamic URL. For instance, if you visit a Web page that displays a message that states: "This page has moved, you will be automatically be taken to the new page". The Webmaster has written a script in to the old Web page that gives the ability to dynamically redirect you to the new page. 

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