Canadian, not a gun owner but here's the gist: To have guns you need a license and a clean criminal record which is automatically checked so long as you are registered to use them (the PAL). If you are convicted of violent or weapon related crime, you lose privileges. The license has a 28 day mandatory waiting period. Canadian gun owners are free to fact check or clarify this for me.
Once registered can use most long guns, shotguns as they are non-restricted for hunting and typical activities like that (of course you'll need to be registered separately to publicly conduct that activity). Restricted and prohibited weapons like handguns, semiautomatic and automatic weapons can only be possessed or acquired for people who use it as specifically necessary for their occupation, someone who does target practice as part of a registered club (restricted only), collectors knowledgeable on the series of equipment and certain exemptions for old hand-me-downs. Any time you move these categories of firearms to another location, legally you need to fill out a form and notify authorities.
Illegal firearms often show up here after being smuggled from across the border, where they seem to give them out like candy in comparison.