In some countries, such as the United States and Japan, a master's degree is a postgraduate academic degree awarded after the completion of an academic program of one to six years in duration. In other countries, such as Sweden and Denmark, a master's degree is an undergraduate academic degree awarded after the completion of an academic program of one to five years in duration. While again in other countries, such as England, Scotland and Ireland, a master's degree can be both an undergraduate academic degree awarded after the completion of an academic program of four (or sometimes five) years in duration, or a postgraduate academic degree awarded after the completion of an academic program of one to two years in duration.

In the recently standardized European system of higher education diplomas, it corresponds to a one to two year (60 to 120 ECTS credits) postgraduate program undertaken after at least three years of undergraduate studies. It provides higher qualification for employment or prepares for doctoral studies. In the USA and Canada, a master's degree entails a one- or two–year program of study in which students would normally enroll after completing a bachelor's degree.

However, in some European countries, a magister is a first degree and may be considered equivalent to a modern (standardized) master's degree (e.g., the German university Diplom/Magister, or the similar 5-year diploma awarded in several subjects in Greek, Spanish, Italian, Polish, and other universities and polytechnics). In the Francophone countries, a DEA is the postgraduate degree and considered equivalent to the master's degree (e.g, In France, the French-Speaking Belgium a DEA is 1-2 years degree taken after the Licence), after the application of Bologna process the DEA had been given a new name: MAS (Master of Advanced Studies). In Switzerland, the old Licence (4 to 5 years in duration) is considered equivalent to the master's degree .

The master of arts (magister artium), master of science (magister scientiæ) and Master of Science in Law degrees are the basic degree types in most subjects, and they may be course-based, research-based, or (more typically) a mixture of the two. A dissertation may or may not be required, depending on the program. There are also degrees of the same level, such as engineer's degrees, which have different names for historical reasons.

Admission to a master's program normally requires holding a bachelor's degree (in the United Kingdom an 'honours' bachelor degree), although relevant work experience may qualify a candidate. Progressing to a doctoral program sometimes requires that the candidate first earn a master's degree. In some fields or postgraduate programs, work on a doctorate begins immediately after the bachelor's degree, but the master's may be earned along the way, as a result of the successful completion of coursework and certain examinations. In some cases the student's bachelor's degree must be in the same subject as the intended master's degree, or in a closely allied discipline; in others, the subject of the bachelor's degree is unimportant.