People sometimes use the terms root word and base word as if they mean the same thing, but they are different. comment on it?

Root Word is etymological, meaning that it is a Word from an older language which evolved into the current Word. A base Word is a Word that has meaning on its own, without prefix or suffix.

Help is a base Word. It can be modified into things like helpful or helpless, but "help" by itself means something.

Helpan is the root Word of help, it's an Old English Word from which "help" is derived.