Health insurance for international students in Canada depends on which province you choose to study in, and what arrangements are made by your educational institution.
Canada has socialized basic healthcare. Basic care such as doctor's visits and hospital visits are covered by provincial healthcare plans, paid for by taxes. In addition to this, many Canadians have extended healthcare insurance to cover things not covered by the basic provincial plans.
Some provinces, such as British Columbia, enroll international students under the provincial Medical Services Plan (MSP). Others, like Ontario, do not. You will want to research the provincial medical services of the province in which you wish to study.
There are a wide variety of potential insurance providers for international students in Canada. Some are offered by the same companies who offer travel insurance, and some are offered by Canada's larger extended healthcare insurance providers. Additionally, many post-secondary institutions have a mandatory extended coverage plan included in their tuition. You will want to check with your educational institution.
Canada's healthcare system is one of the best in the world, so it is worth making sure you have adequate access to it.