The GRE, or the Graduate Record Examination, is a comprehensive national examination that some graduate programs require. It’s a standardized test similar to the SAT. But unlike the SAT, it is not necessarily a requirement for entry into all graduate degree programs. Although presenting a GRE score may give you a leg up in the admissions process, some programs may not require you to write it. For example, Princeton University requires applicants to take the GRE for the Masters in Chemistry degree, but exempts students applying to the Masters in Ecology & Evolutionary Biology program.