VA – The Fire Beneath The Machine

Various Artists
A compilation album is an album (music or spoken-word) featuring tracks from one or more performers, often culled from a variety of sources (such as studio albums, live albums, singles, demos and outtakes.) The tracks are usually collected according to a common characteristic, such as popularity, genre, source or subject matter. When the tracks are all essentially by the same recording artist, a compilation album is often referred to as a retrospective album. Compilation albums may employ traditional product bundling strategies.

http://en.wikipedia.org/wiki/Various_Artists