Can individual chat be disabled for certain users but not channels?

Just to make sure I have got it absolutely right:

  • chat allowed groups: this is for channels? what else does it do?
  • direct message enabled groups: this if for direct “instant messaging”?

So if a group is in “chat allowed” but not in “direct message enabled” they can participate in channels, chat with a moderator who would initiate a chat with them, but not initiate an instant messaging conversation with somebody else?

And those settings are completely independent from “personal messages/topics”, permissions for which are set with other settings?

Asking because the description is kind of unclear in my interface: