ISP
ISP: /I·S·P/ Common abbreviation for Internet Service Provider, a kind of company
that barely existed before 1993. ISPs sell Internet access to the mass
market. While the big nationwide commercial BBSs with Internet access
(like America Online, CompuServe, GEnie, Netcom, etc.) are technically
ISPs, the term is usually reserved for local or regional small providers
(often run by hackers turned entrepreneurs) who resell Internet access
cheaply without themselves being information providers or selling
advertising. Compare NSP.
Courtesy of 'The Jargon File 4.4.7'