Mastering is the last stage in the recording process. Mastering takes all the separate songs for an album and puts them together so that they sound good together. Mastering balances the sound of a CD from song to song so that the CD sounds cohesive. Mastering balances the levels from song to song, making sure that each song is as loud as it needs to be. It also makes sure that the tracks are relatively equal in volume and tone. Mastering might also apply some compression to smooth out the dynamics of an entire song. In many cases some subtle EQ is applied to help polish up the tracks. As Mastering deals only with the final stereo mix down, it is a separate stage from the actual mixing process. Compression and limiting are the most common processes applied during Mastering, along with the aforementioned EQ.