Yes definitely, both of them are quite different. Let us first understand both better. The SAT subject tests are high school-level tests and reflect the high school curricula. These tests indicate a student’s readiness to take college-level courses in specific subject areas. AP Exams, however, assess a student’s college-level knowledge, skills and abilities, learned in the corresponding AP courses. As a result, the topics covered on SAT Subject Tests may differ from those covered on AP Exams.