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A B C D E F G H I J K L M N O P Q R S T U V W X Y Z DAC: A digital-to-analog converter is a device that converts a digital (usually binary) code to an analog signal (current, voltage, or electric charge). Mostly found in CD players, digital music players, and PC sound cards.
daemon: In Unix and other computer multitasking operating systems, this is a computer program that runs in the background, rather than under the direct control of a user; they are usually initiated as background processes. Typically daemons have names that end with the letter "d": for example, syslogd, the daemon that handles the system log, or sshd, which handles incoming SSH connections.
DAO: A Data Access Object is an object that provides an abstract interface to some type of database. It provides some specific operations without exposing details of the database.
DARPA: Defense Advanced Research Projects Agency is an agency of the United States Department of Defense responsible for the development of new technology for use by the military.
DASD: Direct Access Storage Device is a general term for magnetic disk storage devices (mainframe, minicomputer, hard disk drives). The "direct access" means that all data can be accessed directly in about the same amount of time rather than having to progress sequentially through the data.
DAT: A digital audio tape is a type of magnetic tape that uses a scheme called helical scan to record data. A DAT cartridge is slightly larger than a credit card in width and height and contains a magnetic tape that can hold from 2 to 24 gigabytes of data. It can support data transfer rates of about 2 MBps. Like other types of tapes, DATs are sequential-access media. The most common format for DAT cartridges is DDS.
Data: Distinct pieces of information, usually formatted in a special way. Data can exist in a variety of forms, as numbers or text on pieces of paper, as bits and bytes stored in electronic memory, or as facts stored in a person's mind. Strictly speaking, data is the plural of datum, a single piece of information.
data model: Documents and organizes the business data for communication between team members and is used as a plan for developing applications, specifically how data is stored and accessed. It explicitly determines the structure of data or structured data.
data packet: A basic unit of communication over a digital network. It is also called a datagram, a segment, a block, a cell or a frame, depending on the protocol. When data has to be transmitted, it is broken down into similar structures of data, which are reassembled to the original data chunk once they reach their destination.
data rate: Is the rate at which circuits or other devices operate when handling digital information.
database: An organised pool of logically-related data for one or more uses, typically in digital form. It is a system intended to organize, store, and retrieve large amounts of data easily.
DBA: A database administrator is a person responsible for the design, implementation, maintenance and repair of an organization's database. The role includes the development and design of database strategies, monitoring and improving database performance and capacity, and planning for future expansion requirements. They may also plan, co-ordinate and implement security measures to safeguard the database.
DBMS: A database management system is a set of computer programs that controls the creation, maintenance, and the use of a database.
DBS: A database system is a term that is typically used to encapsulate the constructs of a data model, database Management system (DBMS) and database.
DC: Direct Current - An electric current that moves in one direction with constant strength. Batteries are a source of direct current.
DCC: Data Communication Channel is the inband data communication channel in SONET/SDH communication.
DCD: The Document Content Description is an RDF vocabulary designed for describing constraints to be applied to the structure and content of XML documents.
DCOM: Distributed Component Object Model is a proprietary Microsoft technology for communication among software components distributed across networked computers. DCOM, which originally was called "Network OLE", extends Microsoft's COM, and provides the communication substrate under Microsoft's COM+ application server infrastructure. It has been deprecated in favor of the Microsoft .NET Framework.
DDoS: A distributed denial-of-service attack, most often, is one in which a multitude of compromised systems are used by some organized malicious endeavor to attack a single target, usually some online resource, by flooding it with the vast multitude of connection attempts from those compromised systems (called zombies) causing a denial of service (DoS) to legitimate users.
DDR: Is a single data rate SDRAM interface. It has been superseded by DDR2 and DDR3 SDRAM. It is not forward compatible with either DDR2 or DDR3 SDRAM. DDR SDRAM memory modules will not work in DDR2 or DDR3 equipped motherboards and vice versa.
DDR2: Is a double data rate SDRAM interface.
DDR3: Is a triple data rate SDRAM interface.
DDS: Digital Data Storage is the industry standard for digital audio tape (DAT) formats.
decompression: The restoration of data that has undergone compression to its original state.
Default Gateway: Provides an entry point and an exit point in a network. In home computing, an ISP often provides a physical device which both connects local hardware to the Internet and serves as a gateway. Such devices include DSL modems and cable modems.
Desktop: The background on a Windows computer upon which
Icons and new windows are displayed.
DoS: A denial-of-service attack is when an attacker attempts to prevent legitimate users from accessing information or services. By targeting your computer and its network connection, or the computers and network of the sites you are trying to use, an attacker may be able to prevent you from accessing email, websites, online accounts (banking, etc.), or other services that rely on the affected computer.
DRAM: Is dynamic random access memory which is a type of memory that is used in most personal computers.
