Data mart
A repository of data that serves a particular community of knowledge workers. The data may come from an enterprise wide database or a data warehouse.
Data mining
The practice of extracting data from a data warehouse in order to analyze patterns, trends and relationships.
Data modeling
The practice of analyzing an enterprise's data and identifying the relationships among the data.
Datanets
Datanets are generally private networks of land-based telephone lines, satellites or wireless networks that allow corporate users to send data at high speeds to remote locations while bypassing the speed and cost constraints of traditional telephone lines.
Data scrubbing
The practice of monitoring a data warehouse and removing data that is not trustworthy or timely.
Data warehouse
A database that stores large amounts of historical business data.
Dial-Up Access
The connection of a computer or other device to a network through a modem and a public telephone network. The only difference between dial-up access and a telephone connection is that computers are at each end of the connection rather than people. Dial-up access is slower than DSL, ISDN and other advanced connections.
Digital
Transmission of a signal reducing all of its information to ones and zeros and then regrouping them at the reception end. Digital transmission vastly improves the carrying capacity of the spectrum while reducing noise and distortion of the transmission.
Digital Local Telephone Switch
A computer that interprets signals (dialed numbers) from a telephone caller and routes calls to their proper destinations. A digital switch also provides a variety of calling features not available in older analog switches, such as call waiting.
Digital Certificate
A digital document issued by a certification authority that contains the holder's name, serial number, public key and the document's expiration date. Digital certificates are used in public key infrastructure to send and receive secure, encrypted messages.
Digital Signal Processor
Chip that converts analog signals such as sound and light into digital signals.
Digital signature
An electronic signature that uses public key infrastructure to verify the identity of the sender of a message or of the signer of a document.
Digital subscriber line (DSL)
A group of protocols that allow customers and phone companies to exchange data over telephone lines at a high speed. The individual protocols are: asymmetric digital subscriber line (ADSL), symmetric digital subscriber line (SDSL), high-data-rate DSL (HDSL) and single-line DSL (SDSL).
Disaster Recovery
A set of rules and procedures that allow a computer site to be put back in operation after a disaster has occurred. The concept of moving backups off-site constitutes the minimum basic precaution for disaster recovery. The remote copy is used to recover data if the local storage is inaccessible after a disaster.
Discrete Semiconductor
Chip with one diode or transistor.
Disk Mirroring
A data redundancy technique in which data is recorded identically on multiple separate disk drives at the same time. When the primary disk is off-line, the alternate takes over, providing continuous access to data. Disk Mirroring is sometimes referred to as "RAID."
Domain
A domain is a "domain name" that has server records associated with it.
Domain Name
This name identifies an individual site on the Internet and is always comprised of at least two parts, separated by dots, such as IBM.com.
Domain (Top-Level)
Either an ISO country code or a common domain name such as .com, .org or .net.
Dotcom
A company with a strong Web presence that conducts some or all of its business on its website.
DS-1
A digital transmission format that transmits and receives information at a rate of 1,544,000 bits per second.
Duplicate Host
A single host name that maps to duplicate IP addresses.
Dynamic HTML (DHTML)
The combination of the HTML Web-authoring language with languages like Javascript that enable interactivity. DHTML produces Web content that changes with each individual viewing. The same site, for example, could appear different to the viewer depending on conditions such as the geographic location of the reader, the time of day, previous pages viewed by the reader and the user's profile.
