distance learning n. education (esp. at tertiary level) in which contact between students and teacher is principally by correspondence or broadcast programmes [sic], rather than face to face.
-- Oxford English Dictionary
Distance education means education that uses one or more of the technologies listed in paragraphs (1) through (4) to deliver instruction to students who are separated from the instructor and to support regular and substantive interaction between the students and the instructor, either synchronously or asynchronously. The technologies may include--
1. The internet;
2. One-way and two-way transmissions through open broadcast, closed circuit, cable, microwave, broadband lines, fiber optics, satellite, or wireless communications devices;
3. Audioconferencing; or
4. Video cassettes, DVDs, and CD-ROMs, if the cassettes, DVDs, or CD-ROMs are used in a course in conjunction with any of the technologies listed in paragraphs (1) through (3).
-- United States Department of Education