A college minor is a second area of study that does not have to relate to your major. This makes a minor unique from a concentration since concentrations are in subject areas that pertain to the degree you plan to earn. As an example, you might decide to major in Business Administration, with a minor in Biology. Of course, you could also do the opposite with a major in Biology and a minor in Business Administration. While you don't have to declare a minor to earn a college degree, doing so can help you gain valuable information or earn credits that might apply to a graduate degree. Choosing a minor can also be a good option if you can't decide between two somewhat unrelated fields of study and prefer to go with both.