[dnanian]

Well, Smart Update is a copy method, while a Safety Clone is a type of clone. If you have an existing Safety Clone, you can update that Safety Clone with Smart Update, which, as you might expect, means updating it will go faster then if you were to erase and re-copy all the files.

The Safety Clone itself (produced by one of the two Safety Clone copy scripts) is not a full backup. In fact, it's almost the opposite of one -- it's a "checkpoint" of only the operating system files and (mostly) Apple applications, designed to allow you to boot to it to isolate your system from unwanted changes or unstable updates.

One of the Backup copy scripts is the thing to use for a real backup and -- while it can be stored on the same drive as a safety clone, cannot be stored on the same partition -- you can't really have two bootable copies of the OS on the same partition... you really need two partitions.

Does that answer your question?