Name Description
Dashboard: Dashboard is a user-interface feature Apple introduced with the release of Mac OS X 10.4 Tiger. It allows access to all kinds of "widgets" that show the time, weather, stock prices, phone numbers, and other useful data. With the Tiger operating system, Apple included widgets that do all these things, plus a calculator, language translator, dictionary, address book, calendar, unit converter, and iTunes controller. Besides the bundled widgets, there are also hundreds of other widgets available from third parties that allow users to play games, check traffic conditions, and view sports scores, just to name a few.
Data Management: Data management refers to the way individuals, companies, and organizations manage computer data. It includes micro applications, such as data architecture and design, as well as macro applications, including data storage, access, and security. While computer data may be intangible, it can also be valuable. Therefore, it is important for all users to consider how they manage their data. This may involve taking steps such as backing up important files and encrypting personal information.
Data Transfer Rate: The data transfer rate is commonly used to measure how fast data is transferred from one location to another. For example, a hard drive may have a maximum data transfer rate of 480 Mbps, while your ISP may offer an Internet connection with a maximum data transfer rate of only 1.5 Mbps.
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.
DDC Display Data Channel. A collection of protocols for digital communication between a computer display and a graphics adapter that enable the display to communicate its supported display modes to the adapter and that enable the computer host to adjust monitor parameters, such as brightness and contrast.
Dead Pixel: An individual pixel in a sensor that does not respond to light and appears as black in an image.
Decibels: Our ears detect changes in volume in a non-linear fashion. A decibel is a logarithmic scale of loudness. A difference of 1 decibel is perceived as a minimum change in volume, 3 db is a moderate change, and 10 decibels is perceived by the listener as a doubling of volume. Decibels are designated by the letters: db.
Default: This term is used to describe a preset value for some option in a computer program. It is the value used when a setting has not been specified by the user.
Desktop Computer: A desktop computer is a computer system designed to be used at a table or desk. Some desktop computers have a separate monitor and system unit, while others are "all-in-one" models, in which the monitor is built into the computer. All-in-one computers are designed to sit on a desktop, while system units are usually placed on the ground. Both types of desktop computers include a keyboard and mouse as input devices.
Desktop: Your computer's desktop is much like a physical desktop. Your computer's desktop serves this purpose - to give you easy access to items on your hard drive. It is common to store frequently used files, folders, and programs on your desktop. This allows you to access the items quickly instead of digging through the directories on your hard drive each time you want to open them.
DHCP Stands for "Dynamic Host Configuration Protocol." A network server uses this protocol to dynamically assign IP addresses to networked computers. The DHCP server waits for a computer to connect to it, then assigns it an IP address from a master list stored on the server. DHCP helps in setting up large networks, since IP addresses don't have to be manually assigned to each computer on the network. Because of the slick automation involved with DHCP, it is the most commonly used networking protocol.
Digital Camera: A digital camera is an electronic device that captures images in a digital format. It works in a similar way to a film-based camera, but uses a sensor called a CCD to record images rather than a strip of film. Once an image or video is captured by the CCD, it is saved to a memory card, such as an SD card. Images and videos saved to the memory card can be imported to a computer using a standard USB cable.
Digital Coaxial Connection: A digital coaxial connection refers to a wired connection that is used for transferring digital audio signals (such as PCM, Dolby Digital, and DTS) from a source device, such as CD or DVD player and an AV receiver or Surround Sound Preamp/Processor. Digital Coaxial Connections use RCA-style connection plugs.
Digital Optical Connection: A digital optical connection refers to a fiber-optic connection that is used for transferring digital audio signals (such as PCM, Dolby Digital, and DTS) from a source device, such as CD or DVD player and an AV receiver or Surround Sound Preamp/Processor. Also known as Toslink.
Direct 3D: Direct3D is an application program interface developed by Microsoft that provides a set of commands and functions for manipulating 3D objects. By using Direct3D commands, software developers can take advantage of many prewritten functions. This allows programmers to write significantly less code than if they had to write all the functions from scratch. Direct3D makes it relatively easy to manage three-dimensional objects, including lighting and shadows as well.
DLP A video projection technology, developed by Texas Instruments, that utilizes a chip, referred to as a DMD (Digital Micromirror Device). In essence, every pixel on a DMD chip is a reflective mirror. The video image is displayed on the DMD chip. The micromirrors on the chip (remember: each micromirror represents one pixel) then tilt very rapidly as the image changes. This process produces the grayscale foundation for the image. Then, color is added as light passes through a high-speed color wheel and is reflected off of the micromirrors on the DLP chip as they rapidly tilt towards or away from the light source. The degree of tilt of each micromirror coupled with the rapidly spinning color wheel determines the color structure of the projected image. As the amplified light bounces off the micromirrors, it is sent through the lens and can be projected on a large screen.
DNS Stands for "Domain Name System." The reason the Domain Name System is used is because Web sites are actually located by their IP addresses. For example, when you type in "," the computer doesn't immediately know that it should look for Adobe's Web site. Instead, it sends a request to the nearest DNS server, which finds the correct IP address for "" Your computer then attempts to connect to the server with that IP number.
Dolby Digital EX: Dolby Digital EX is based on the technology already developed for Dolby Digital 5.1. This process adds a third surround channel that is placed directly behind the listener.
Dolby Pro Logic IIz: Dolby Pro Logic IIz processing is an enhancement that extends surround sound vertically. Dolby Pro Logic IIz offers the option of adding two more front speakers that are placed above the left and right main speakers. This feature adds a "vertical" or overhead component to the surround sound field (great for rain, helicopter, plane flyover effects). Dolby Prologic IIz can be added to either a 5.1 channel or 7.1 channel setup.
Dolby True HD: Dolby TrueHD is a high definition digital-based surround sound format that supports up to 8-channels of surround decoding and is bit-for-bit identical to a studio master recording. Dolby TrueHD is one of the several audio formats designed and employed by Blu-ray Disc and HD-DVD technologies. Dolby TrueHD is compatible with the audio portion of the HDMI interface.
Domain: A domain contains a group of computers that can be accessed and administered with a common set of rules. For example, a company may require all local computers to be networked within the same domain so that each computer can be seen from other computers within the domain or located from a central server. Setting up a domain may also block outside traffic from accessing computers within the network, which adds an extra level of security.
Dongle: This is a hardware device that plugs into the USB port or PCMCIA of a computer. Mainly used to connect a device for networking purposes.  Can be used to identify a device such as a Bluetooth transceiver, Wireless adapter, or USB to Ethernet adapter to the computer.
Download: This is the process in which data is sent to your computer. Whenever you receive information from the Internet, you are downloading it to your computer.
DPI Dots Per Inch. A measure of resolution that refers to the number of dots a printer can print in an inch of output. Higher resolution means more dots per inch. Often mistakenly used for PPI, or pixels per inch. It more correctly applies to output devices that print with dots, such as inkjet printers.
DPI Stands for "Dots Per Inch." DPI is used to measure the resolution of an image both on screen and in print. As the name suggests, the DPI measures how many dots fit into a linear inch. Therefore, the higher the DPI, the more detail can be shown in an image. In terms of gaming, DPI is a measurement of how sensitive a mouse is. The higher the DPI, the farther the curson on your screen will move when the mouse is moved. A mouse with a higher DPI setting detects and reacts to smaller movements.
Driver: This term usually refers to the person behind the wheel of a moving car. In the computer world, however, a driver is a small file that helps the computer communicate with a certain hardware device. It contains information the computer needs to recognize and control the device.
DSL Stands for "Digital Subscriber Line." It is a medium for transferring data over regular phone lines and can be used to connect to the Internet. However, like a cable modem, a DSL circuit is much faster than a regular phone connection, even though the wires it uses are copper like a typical phone line.
DSLR: Digital Single Lens Reflex. A camera that uses a mirror to intercept the light from the camera's lens and send it to a focusing screen for inspection by the photographer's eye. The reflex mirror swings up and out of the way when the picture is taken, allowing the light to reach the digital sensor.
DTS: DTS is a 5.1 channel encoding and decoding system similar to Dolby Digital 5.1, but DTS uses less compression in the encoding process. As a result, many feel that DTS has a better result on the listening end.
\nIn addition, while Dolby Digital is mainly intended for the Movie Soundtrack experience, DTS is also used in the mixing and reproduction of musical performances.
Dual Band IR: Dual band extenders work on both frequencies, making them work with virtually everything. This is a good option, especially when there is any question about what frequency your device uses.
DVD Recorder: A DVD recorder typically refers to a standalone unit that resembles and functions very much like a VCR, but records onto a DVD disc, rather than a video tape. All DVD recorders can record from any analog video source (most can also record video from digital camcorders via firewire, iLink, IEEE1394, DV connection).
DVD Region Code: Region Codes are a DVD coding system enforced by the movie industry that is intended to preserve movie distribution rights and agreements.
\nDVD players and DVDs are labeled for operation on within a specific geographical region in the world. For example, the U.S. is in region 1. All DVD players sold in the U.S. are made to region 1 specs. Region 1 players can only play region 1 discs.
DVD: DVD stands for Digital Versatile Disc. DVDs can be used for storing video, audio, still image, or computer data.
DVI: Stands for "Digital Video Interface." DVI is a video connection standard created by the Digital Display Working Group (DDWG).  DVI is capable of supporting analog and digital signals depending on the devices themselves.
\nThere are three types of DVI connections:
\n1) DVI-A (for analog)
\n2) DVI-D (for digital)
\n3) DVI-I (integrated, for both analog and digital).
\nThe digital video interface supports high bandwidth signals, over 160 MHz, which means it can be used for high resolution displays such as UXGA and HDTV. You may find DVI ports on video cards in computers as well as on high-end televisions.
DVR: Stands for "Digital Video Recorder." A DVR is basically a VCR that uses a hard drive instead of video tapes. It can be used to record, save, and play back television programs. Unlike a VCR, however, a DVR can also pause live TV by recording the current show in real time. The user can choose to fast forward (often during commercials) to return to live television.
\nMost satellite and cable TV companies offer a DVR as an option with their digital television packages. Since cable boxes already provide program listings through some kind of TV guide interface, most DVRs allow users to use the guide to schedule recordings. For example, a user can use the remote to search through the guide's program listings for the current week and select the shows he would like to record.