Barn/Show/Registered Names

I'm wanting to make sure I have my name terminology figured out, but I'm not sure...

Barn Name is just what you call your horse everyday.
Registered Name is what's on the paperwork.
Those are easy.

But I've started noticing that people are saying "show name" as well...
Is that for non-registered horses to have a fancier name when they're out?
Or for any horse, say, if you don't care for their registered name?

Thanks!