Glossary
WSUS target group
The group a host belongs to on the internal Windows update server, which decides which approved updates it receives and in which wave.
Also calledupdate target group · deployment ring
A host's assignment to a group on the internal Windows update server. The group determines which updates have been approved for it and at which stage.
In practice this assignment is often the only documentation that exists for "which wave does this host update in" — particularly where groups were built as deployment rings: pilot, then secondary systems, then core.
Which is why it is worth showing beside the host in the coordination tool as well. It does not change the schedule, but it answers "why did this host not get the update?" faster than any other check.