Data: Computer data is information processed or stored by a computer. This information may be in the form of text documents, images, audio clips, software programs, or other types of data. Computer data may be processed by the computer's CPU and is stored in files and folders on the computer's hard disk. At its most rudimentary level, computer data is a bunch of ones and zeros, known as binary data. Because all computer data is in binary format, it can be created, processed, saved, and stored digitally. This allows data to be transferred from one computer to another using a network connection or various media devices. It also
does not deteriorate over time or lose quality after being used multiple times.

DAC:Stands for "Digital-to-Analog Converter" and is often pronounced "dac." Since computers only recognizedigital information, the output produced by computers is typically in digital format. However, some output devices only accept analog input, which means a digital-to-analog converter, or DAC, must be used. The most common use for a DAC is to convert digital audio to an analog signal. This conversion typically takes place in the sound card, which has a built-in DAC. The digital signal, which is basically a stream of ones and zeros, is transformed into an analog signal that might take the form of an electrical charge. This electrical charge is recognized by most speaker inputs and therefore can be output to a speaker system.

Dark backup: A dark backup is one that can be run automatically without manual intervention.

Database:
A database is a data structure that stores organized information. Most databases contain multiple tables, which may each include several different fields. For example, a company database may include tables for products, employees, and financial records. Each of these tables would have different fields that are relevant to the information stored in the table.

DDR3: Stands for "Double Data Rate Type 3." DDR3 is a type of SDRAM that is used for system memory. It is available in both DIMM and SO-DIMM form factors. DDR3 RAM is similar to DDR2 RAM, but uses roughly 30% less power and can transfer data twice as fast. While DDR2 memory can transfer data at up to 3200 MBps (megabytes per second), DDR3 memory supports maximum data transfer rates of 6400 MBps. This means computers with DDR3 memory can transfer data to and from the CPU much faster than systems with DDR2 RAM. The faster memory speed prevents bottlenecks, especially when processing large amounts of data. Therefore, if two computers have the same processor clock speed, but different types of memory, the computer with DDR3 memory may perform faster than the computer with DDR2 memory.

Debian- Debian is an operating system composed of free software mostly carrying the GNU General Public License

Dial-up: (of a computer system or service) used remotely via a telephone line.

DirectX- DirectX is a set of standard commands and functions that software developers can use when creating their programs. While any Windows-based software program can include DirectX commands, they are usually used in video games. For example, developers may use DirectX for controlling video playback, sound effects, and peripheral input (such as a keyboard, mouse, or joystick). By incorporating DirectX functions into a computer game, programmers can use predefined commands to manage the video and sound of their game, as well as user input. This makes it easier for programmers to develop video games and also helps the games look more uniform, since DirectX games use many of the same commands

DNS:
Stands for "Domain Name System." The primary purpose of DNS is to keep Web surfers sane. Without DNS, we would have to remember the IP address of every site we wanted to visit, instead of just the domain name. Can you imagine having to remember "17.254.3.183" instead of just "apple.com"? While I have some Computer Science friends who might prefer this, most people have an easier time remembering simple names.

DOS- disk operating system, refer to an operating system software used in most computers that provides the abstraction and management of secondary storage devices and the information on them

DPI: In computers, dots per inch (dpi) is a measure of the sharpness (that is, the density of illuminated points) on a display screen . The dot pitch determines the absolute limit of the possible dots per inch. However, the displayed resolution of pixel s (picture elements) that is set up for the display is usually not as fine as the dot pitch. The dots per inch for a given picture resolution will differ based on the overall screen size since the same number of pixels are being spread out over a different space. Some users prefer the term "pixels per inch ( ppi )" as a measure of display image sharpness, reserving dpi for use with the print medium.

Domain: A domain is a set of computers on a network that are managed as a unit. On the Internet, a domain is defined by an IP or URL address. The way users encounter a domain is through the domain name.

Driver: A Driver is a program that interacts with a particular device or special kind of software. The driver contains the special knowledge of the device or special software interface that programs using the driver do not.
DVD:
Stands for "Digital Versatile Disc." It can also stand for "Digital Video Disc," but with the mulitple uses of DVDs, the term "Digital Versatile Disc" is more correct. Yep, the technology naming people just love to confuse us. A DVD is a high-capacity optical disc that looks like a CD, but can store much more information. While a CD can store 650 to 700 MB of data, a single-layer, single-sided DVD can store 4.7 GB of data. This enables massive computer applications and full-length movies to be stored on a single DVD.
The advanced DVD formats are even more amazing. There is a two-layer standard that doubles the single-sided capacity to 8.5 GB. These disks can also be double-sided, ramping up the maximum storage on a single disc to 17 GB. That's 26 times more data than a CD can hold! To be able to read DVDs in your computer you'll need a DVD-ROM drive. Fortunately, DVD players can also read CDs. To play DVD movies on your computer, you'll need to have a graphics card with a DVD-decoder, which most computers now have.