Cactus is just an audio file player. But it has some features that makes it different from other players.
There are music databases and there are players like xmms with a small and leightweight, skinable GUI.
Cactus combines these two types in one player! With Cactus you can read your music collection into a database, create a playlist by browsing/searching
it and finally switch to player view(F2-Key).