What characterizes a Mobile Account?
Mobile Account home directory trees are stored locally (normally under /Users) but are synced with a home directory tree on the server.

Other than local files for the user home (which is good if you are using programs that depend on local disk for performance or other reasons), I can't remember any special properties other than the fact that you have two copies of the user's files (which doesn't really count as a backup). Both types of accounts can be managed.