IB stands for International Baccalaureate while AP stands for Advanced Placement. Many of the high schools in countries such as in Canada, as well as the United States, offer an Advanced Placement program that is actually a college-level program. The Good Schools Guide International considers this program to be a rigorous one when it is compared to some other general courses.
AP, on the other hand, is also one of the courses that are widely preferred in the United States. This also earns credit points from the colleges, and it will also help students to get a fair chance for admission.
International Baccalaureate programs train students to be on all rounds, as it even opens up many avenues to take up some research and CAS courses, which actually have extracurricular exposure. Advanced Placement only offers an external assessment exam, while internal assessment is considered important by Internal Baccalaureate courses.