I did a little research and came up with this.
There are 3 categories for firearms in Canada. Allowed, restricted and prohibited.
Handguns with barrels shorter than 4-inches, fully automatic, converted automatics, and assault-type weapons are "prohibited", but "prohibited" doesn't mean you can't own one, just that they're the really scary guns, and you need to jump through more hoops to obtain one.
All restricted and prohibited firearms have to be registered.