In college, you declare a major (some people do more than one), which is your primary field of study.
Examples are Chemistry, Business Management, Software Engineering, and Music. Your major is the core of your college education, and emphasized over other classes.
The college I attended had plenty of general classes, but over half the courses I took were about computers.
A minor is a secondary emphasis of study. I had a math minor, so that required Calculus 1 and 2, along with 15 credit hours (which comes out to 4 or 5 classes) of mid-high level math.
