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.