First introduced circa 1999, the original Napster operated using a centralized directory, or index of files available for sharing. The directory was located on a centralized server (or set of servers), to which various individual user computers — or “peers” — could connect via the Internet. An individual user could download the Napster software, connect to the server, and then send a query for a particular file she wanted to obtain — such as a song title. The server would respond with information indicating which other peers had the file. The user who made the query could then request a copy of that file directly from the other peer, which would respond by providing the file itself.
The original Napster ceased operations shortly after the U.S. Court of Appeals for the Ninth Circuit's decision in A&M Records, Inc. v. Napster, Inc. In that case, the district court issued a preliminary injunction on the grounds that the plaintiffs were likely to be able to establish Napster's liability for contributory (i.e., secondary) copyright infringement. The district court's decision was based largely on the fact that Napster utilized a central server on which it maintained the index of files available for sharing.
On appeal, the Ninth Circuit affirmed in late 2003.
Napster was re-launched as a fee-based music download service in 2003.