One of the most practical collection of features in Pro Tools has to do with creating and using Groups — you can group tracks, and whatever actions you perform on one track will also take place on any grouped tracks. You can have groups where only mix functions affect the grouped the, groups where edit functions affect the grouped track, and groups where both edit and mix functions affect the grouped tracks.
However, there are frequent instances where you might want to change something on one track within a group without affecting the other tracks in the group. For example, you might have drum tracks grouped in the Mix window. When you move one drum track’s fader (say, the snare track), all the drum track faders move along with it. But what if you just want to make the snare louder without also turning up all the other tracks in the drum group?
The solution is to control-click (Mac) or Start-click (Windows) the control you want to change on the particular track you want to isolate. That control will be temporarily “isolated” from the group and you can move it independently.
You can also right-click on the item to temporarily isolate it and modify its setting without affecting the rest of the group.