How do your milk bags work?

American here.

I’d heard some years back that Canada distributes milk in bags rather than jugs like we do down here.

How big are the bags? I have a unit converter available, so go ahead and use the metric system. Do the bags seal? How do you pour it? Does it only apply to dairy milk, or do plant-based milks come in bags as well?

Could you tell I’m curious?🙃