How you apply to study in Canada depends on your university and study level. If you are applying to a university in Ontario, you will apply through the Ontario Universities`' Application Centre (OUAC), a central application platform. Outside of Ontario, you generally apply to universities directly. The minimum eligibility criteria, deadlines, and application requirements depend on the university (and the program).
As an international student, you will need to apply at a DLI – Designated Learning Institution. A DLI has the authorization to teach international students and issue the Letter of Acceptance that you need for a Canadian student visa. If you are applying to universities and programs in Ontario, you will apply through the Ontario Universities’ Application Centre (OUAC). Outside Ontario, you will typically apply directly to the university.