Corn vs popcorn

Hi guys I'm a T2, and trying to control myself so have a question that I can not find an answer to.

So to my understanding corn is "bad" for you but they say popcorn is a good healthy snack, I LOVE popcorn but i don't go for the full butter I've always eaten no to light butter..

But is it a good healthy snack for us? Will it effect our sugar considering it used to be "corn"

I hope my question is clear

Thanks in advance!