data - Information that can be used to generate calculations or to make decisions; plural of datum.

 

database - One or more large structured sets of persistent data, usually associated with software to update and query the data.

 

data encryption - Putting data into a secret code so it is unreadable except by authorized users.

 

Data miner - application designed to collect information about the user in real time. This may or may not include transmission of the information to a remote server. The information collected is disclosed to the user via privacy policy and/or licensing in the End-User Licensing Agreement (EULA). Most people do not read the EULA before installing software and are unaware of the practice.

 

Denial of Service – an attack on a computer system intended to reduce, or entirely block, the level of service that legitimate clients can receive from that system.

 

Desktop - In Windows, the whole computer screen, which represents an office desktop. With a graphical interface, the icons on the screen resemble objects that would be found on a real desktop, such as file folders, a clock, etc.

 

Desktop Gadget - light-weight single-purpose applications that can sit on the user's computer desktop, or are hosted on a Web page. According to Microsoft, it will be possible for the different types of gadgets to run on different environments without modification, but this is currently not the case.

 

Desktop Toolbar - On the Windows Taskbar, it contains all of the shortcuts on your desktop and organizes them into one convenient place.

 

device driver - Software to control a hardware component or peripheral device of a computer, such as a disk or printer.

 

default - An option a program uses unless another is specified.

 

dialer – an application designed to change the user's Dial Up Networking settings to dial numbers that the user does not know, to connect to a number in stealth, and/or to avoid being detected by the user such as dialing expensive connections where the user has not authorized the connection.

 

digital signature - code created from both the data to be signed and the private key of the signer. This code is unique for each new piece of data. Even a single comma added to a message changes the digital signature for that message. Successful validation of your digital signature by appropriate software not only provides evidence that you approved the transaction or message, but also provides evidence that the data has not changed since you digitally signed it. A digital signature has nothing to do with a handwritten signature, although it can sometimes be used for similar legal purposes.

 

digital single-lens reflex camera (DSLR) - a digital camera that uses an automatic mirror system and pentaprism to direct light from the lens through the viewfinder. (See "single-lens reflex")

 

digital zoom - Enlarging of an image that requires the camera to double the size of the pixels. Due to the doubling of pixels the image begins to become fuzzier as you enlarge. Try to avoid using digital zoom because the image suffers. (compare "optical zoom")

 

DIMM {dimm} [Dual Inline Memory Module] - Small circuit boards carrying memory integrated circuits, with signal and power pins on both sides of the board. (contrast "SIMM")

 

DIP {dip} [Dual Inline Package] - Computer chip package, rectangular in shape and having an equal number of pins attached to the long sides of the package.

 

direct memory addressing [DMA] - Method of transferring data from one memory area to another without having to go through the central processing unit. Computers with DMA channels can transfer data to and from devices much more quickly than those in which the data path goes through the CPU.

 

directory - A node in a hierarchical file system. A place where you put your files, also known as a folder.

 

disc - An optical storage device (CD or DVD).

 

disk - A magnetic storage device.

 

disk (disc) drive - A peripheral device that reads and writes disks.

 

diskette - floppy disk.

 

display adapter - Hardware which controls the display of information on the monitor (i.e., a video card).

 

DLL {dee-ell-ell} [dynamically linked library] - Library that is linked to application programs when they are loaded or run rather than as the final phase of compilation. The same block of library code can be shared between several tasks rather than each task containing copies of the routines it uses.

 

DMA {dee-em-ay} - (see "direct memory addressing")

 

DNS {dee-en-ess} [Domain Name System] - Network service used to convert system names to numeric Internet Protocol (IP) addresses.

 

domain name - The unique name that identifies an Internet site. Domain names always have two or more parts, separated by dots. The part on the left is the most specific, and the part on the right is the most general. A given machine may have more than one domain name but a given domain name points to only one machine. Domain names follow the format of the Fully Qualified Domain Name (FQDN) system.

 

dongle {dong´gl} - A security or copy protection device for proprietary software consisting of a serialized read-only memory device in a connector shell, which must be connected to either a printer port or serial port while the program is run. Programs that use a dongle query the port at startup and at programmed intervals thereafter, and terminate if it does not respond with the dongle's programmed validation code. Thus, users can make as many copies of the program as they want but must pay for each dongle. These devices have become rare as the industry has moved away from copy-protection schemes in general and use activation requirements.

 

DOS {doss} [Disk Operating System] - Software that translates the user's commands and allows application programs to interact with the computer's hardware. DOS runs on all computers, even those running Windows 9x.

 

dot matrix - Printer that employs a movable printhead with pins, or wires, that shoot out and strike a ribbon. Each strike of a single pin creates a dot on the paper. Characters are formed as a pattern, or matrix, of dots.

 

dot pitch - The distance between a dot and the closest dot of the same color (red, green or blue) on a color monitor. The smaller the dot pitch, the crisper the image.

 

dots per inch (DPI) - The resolution of an image. The higher the DPI, the better the detail of an image. It is a measurement of the number of dots found in a one-inch square of an image. If you want a decent print, you should use an image with at least 300 DPI.

 

double-click - To click the mouse button twice in rapid succession; used to open programs and files.

 

double-density disk - Low-capacity floppy disk that stores less data than a high-density floppy disk.

 

down - Not operating.

 

download - Transfer a file from a remote computer to your computer, using a terminal program and a transfer protocol.

 

Downloader - a program that automatically downloads and runs and/or installs other software without the user's knowledge or permission. In addition to downloading and installing other software, it may download updated versions of itself.

 

DPI (see "dots per inch")

 

drag and drop - A common method for manipulating files in Windows. The user moves the pointer over an icon representing a file and presses the left mouse button. The button is held down while the pointer is moved (dragged) to another place, usually a directory, viewer or an icon for some application program, and then it is released (dropped).

 

DRAM {DEE-ram} [dynamic random access memory] - Type of memory in which the information is stored in capacitors on an integrated circuit.

 

driver - (see "device driver")

 

DSL {dee-ess-ell} [Digital Subscriber Line] - A technology that enables high-speed transmission of digital data over regular copper telephone lines. (see also "HDSL" and "ADSL")

 

DSLR - (see "digital single-lens reflex camera")

 

Dual-Core - a CPU that includes two complete execution cores per physical processor. It combines two processors and their caches and cache controllers onto a single integrated circuit (silicon chip). It is basically two processors, in most cases, residing reside side-by-side on the same die.

 

DVD {dee-vee-dee} [Digital Versatile Disc or Digital Video Disc] - An optical storage medium which has greater capacity and bandwidth than a CD. DVDs can be used for multimedia and data storage. A DVD has the capacity to store a full-length film with up to 133 minutes of high quality video plus audio.

 

DVD Recorder (Burner) - produces DVD discs playable in stand-alone video players or DVD-ROM drives. ("DVD recorder" may also refer not just to the drive unit, but also to consumer set-top devices which record video onto DVD media.)