Major, Concentration
An academic major or concentration is the student's main field of specialization during his or her undergraduate studies. The department offering the major defines a framework for this specialized portion of a student's studies, including a certain number of required courses and a certain number of freely chosen courses relevant to the major. 
The main difference between a major and a concentration is that a concentration requires fewer departmental course points than a major.
Columbia College students can graduate with a major or a concentration; however General Studies students must have a major and can also have a concentration. 
Interdepartmental majors are major offered by two departments that allow students to stress areas of particular concern in both departments. 
Minor
An academic is the student's secondary field of study or specialization during his or her undergraduate studies. As with an academic major, the department lays out a framework of required classes or class types a student must complete to earn the minor. Only the School of Engineering & Applied Science offers minors in Columbia University.
Academic minors and majors differ in that the former is subordinate to the latter. Some students will prepare for their intended career with their major, while pursuing personal interests with a minor. Other students pursue a minor to provide specific specialization and thus make themselves more attractive to employers. For example, secondary education teachers often major in their subject area, as history or chemistry or mathematics, and minor in education.
Premedical Concentration
The purpose of a premedical concentration is to allow students who are completing the various requirements for medical school to be able to benefit fully from a liberal arts curriculum.