Overview of Departmental Concentrations
"All Princeton undergraduates have to select a concentration — our term for a major. This is the departmental program of study that leads to your degree, either a Bachelor of Arts (A.B.) or a Bachelor of Science in Engineering (B.S.E.). If you are in the School of Engineering and Applied Science, you will choose your concentration at the end of freshman year. If you are in the A.B. program, you will choose in the spring of your sophomore year".