How best to back up files?

I am unsure as to a good way to backup my files for such a task.

I saved a copy as: GrabberTEMP.cpp but this threw back some issues with the compiler.
Should I simply be saving an exact copy in a, say, folder in my documents?
Or is there a better way? Thank you.

for backuping your code files I recommend learning how to use GitHub and source control