Exchange: OSU students "switch places" with students from international institutions. Placement in these programs often depends on how many students the other institution will be able to send to OSU. Students going on exchange programs will pay tuition to OSU for their time abroad.
Study Abroad: This term is broadly used to refer to any type of overseas study program. However, it can also refer to a specific type of program that differs from exchange or faculty led. When a specific program is labeled as a "study abroad", there is no exchange/switching places between students and schools. Students typically pay tuition to the host institution or a third party provider.
Faculty Led: OSU faculty teach a course abroad. Students pay OSU tuition. How the course(s) apply to individual degree programs varies depending on subject taught.