What are EBS snapshots?

I found this info in the document Oracle® Applications Maintenance Utilities Release 12.1 Part No. E13676-02 There are two types of snapshots: APPL_TOP snapshotsand global snapshots.

An APPL_TOP snapshot lists patches and versions of files in the APPL_TOP.

A global snapshot lists patches and latest versions of files in the entire Applications system (that is, across all APPL_TOPs).

Both APPL_TOP snapshots and global snapshots may be either current view snapshots or named view snapshots.

A current view snapshot is created once and updated when appropriate to maintain a consistent view.

A partial view snapshot allows you to synchronize only selected files from a current view.

A named view snapshot is a copy of the current view snapshot at a particular time (not necessarily the latest current view snapshot), and is not updated.