A limit is a fundamental concept in calculus. Unlike a limit mentioned above (as in a series or sequence), a limit of a function in calculus takes on a somewhat different meaning. In particular, a limit of a function can be described as the following: If f(x) is a function defined around a point c (but may not be at c itself), the formal limit equation becomes:

Thus, the number L is called the limit of f(x) when x goes to c.