The difference between two things is the way in which they are unlike each other. the degree to which one person or thing differs from another: [countable; usually singular] The difference in their ages is about six months. [uncountable] There isn't much difference between one politician and another.

Understanding the Context

In math, a difference is the remainder left after subtracting one number from another. Chimps and gorillas are both apes, but there are a lot of differences between them.