Ap is a preparatory course in American universities, ib is an international preparatory certificate course, a-level is an advanced level of general education certificate, and bc is a high school course in British Columbia, Canada. Ap can apply for American universities, ib and A-level can apply for universities in the world as long as English is the teaching language, and bc is a Canadian university. However, if you apply for an American university, you'd better use the sat.