Flights within ACs home country are domestic.

Flights between Canada and any other country than the U.S. are international.

Flights between Canada and the U.S. are called transborder because they needed a word other than international to tell you to go to through US Pre-clearance.

Flights operated by an airline between 2 countries that aren't its home countries are called fifth freedom flights because special permission from those countries is generally required to pick up passengers not related to the airline's home country.

I think those are the terms you're looking for.