Sometimes stems are referred to as tracks, which can get confusing as the entire project or song is also on occasion referred to as a track.
The below example is of 8 stems.
The below example is of 6 stems.
A revision is a term used to describe a round of changes you may want to make after your mix has been delivered.
This can be any part of the mix and will usually be due to personal preference, which is why we include a revision round free with each mix package to ensure you are fully happy with your final mix.
Each revision round is limited to 6 separate changes. This is to ensure it is a speedy process and to give some protection to the engineers time after the initial mix has been delivered.