Board Thread:General Discussion/@comment-10811146-20150516204009/@comment-5389811-20150725131609

A cannon is an artillery weapon which uses explosives to launch projectiles.

Meanwhile canon is a little hard to explain but it essentially means official, true to the original, within the rules. Anything non-canonical is regarded as unrelated or not part of the "official" storyline, for example Scooby and Shaggy's appearances in Laff-a-Lympics are non-canonical (they aren't alluded to anywhere outside of that show).

I hope I didn't completely botch that explanation. Others could probably do better. It's one of those things you understand but can't explain. Like why people love Harry Styles or Kanye West so much.