Good link Tony. Some may also know by the name Cakewalk, Sonar or Logic and there a number of other ones out there. Basically allows you to record MIDI or Audio data. You can record your whole performance at once on to a single track or the way we do which is one "track" at a time. For example, track 1 = Piano part. Track 2 = the bass line, Track 3 = Acoustic Guitar, Track 4 = Percussion, etc.

For more info:
Cakewalk
Logic Pro