A Snapshot is a copy of a saved state of a Slot and is stored in the Library like any other Clip. They contain the source, Plugins and their set-ups and the Drivers and their set-ups as a Library item which can be restore/loaded just like any other clip.
There are 2 types of patches
1. Bus Rack Patch
2. Aux Rack Patch
A Bus Rack Patch is a snapshot of a Bus state. They contain Snapshots of all the Slots in the Bus as well as the Bus set up at the time and can be assigned to a Project.
They are than made available in the Patches list, with an image of the rack at that time, and can be filtered by Project.
This is the Patch dialog, which display information and reports states.