This directory presents installed snap packages.

It has the following structure:

/var/lib/snapd/snap/bin                   - Symlinks to snap applications.
/var/lib/snapd/snap/<snapname>/<revision> - Mountpoint for snap content.
/var/lib/snapd/snap/<snapname>/current    - Symlink to current revision, if enabled.

DISK SPACE USAGE

The disk space consumed by the content under this directory is
minimal as the real snap content never leaves the .snap file.
Snaps are *mounted* rather than unpacked.

For further details please visit
https://forum.snapcraft.io/t/the-snap-directory/2817