If I recall right, you used to pick a music directory, and whatever you had there would be indexed and made available to all for downloading. Everything you downloaded would go into that directory as well. Once you find a file you wanted to download, you didn’t download from a pool of people like with bittorrent, but from that one specific user.

If you click on a username, either while searching or while downloading, you could browse everything Napster had indexed. If people didn’t configure Napster right, you could browse their whole C:\ drive. Good times.