D

De facto standard: An e-learning specification that hasn't been officially established by an accrediting agency but that is accepted and used as a standard by a majority of practitioners.

Default: A setting that the computer system uses automatically, unless it is changed by the user.

Delivery: Any method of transferring content to learners, including instructor-led training, Web-based training, CD-ROM, books, and more.

Desktop videoconferencing: Videoconferencing on a personal computer.

Development: 1) Learning or other types of activities that prepare a person for additional job responsibilities and/or enable him to gain knowledge or skills. 2) The creation of training materials or courses, as in content development or e-learning development.

Dial up: To open a connection between a user's computer and another computer via a modem.

Digital: An electrical signal that varies in discrete steps in voltage, frequency, amplitude, locations, and so forth. Digital signals can be transmitted faster and more accurately than analog signals.

Digital Divide: The gap that exists between those who can afford technology and those who cannot.

Discussion boards: Forums on the Internet or an intranet where users can post messages for others to read.

Disc/Disk: See floppy disk or CD-ROM.

Disk drive: The part of a computer that reads and writes data onto either a floppy disk, a hard disk, or an optical disk (CD, CD-ROM, DVD, DVD-ROM, WORM, and so forth).

Distance education: Educational situation in which the instructor and students are separated by time, location, or both. Education or training courses are delivered to remote locations via synchronous or asynchronous means of instruction, including written correspondence, text, graphics, audio- and videotape, CD-ROM, online learning, audio- and videoconferencing, interactive TV, and FAX. Distance education does not preclude the use of the traditional classroom. The definition of distance education is broader than and entails the definition of e-learning.

Distance learning: The desired outcome of distance education. The two terms are often used interchangeably.

Download: (noun) A file that's transferred or copied to a user's computer from another connected individual computer, a computer network, a commercial online service, or the Internet. (verb) To transfer or copy a file to a user's computer from another connected individual computer, a computer network, a commercial online service, or the Internet.

DS (Digital Signal): The rate and format of a digital signal, for example, DS-1 or DS-3. Often used synonymously with T, as in T1 or T3, although the T technically refers to the type of equipment. See T1 and T3.

DSL (digital subscriber line): A broadband Internet access method that sends data over standard phone lines at speeds up to 7 Mbps. DSL is available to subscribers who live within a certain distance of the necessary router.

DVD (digital versatile disc): Optical disks that are the same size as CDs but are double-sided and have larger storage capacities.

DVI (digital video interactive): A format for recording digital video onto compact disk, allowing for compression and full-motion video.