Calculus is a central branch of mathematics.
Calculus is built on two major complementary ideas, both of which rely critically on the concept of limits.
The first is differential calculus, which is concerned with the instantaneous rate of change of quantities with respect to other quantities, or more precisely, the local behavior of functions.
This can be illustrated by the slope of a function's graph.
The second is integral calculus, which studies the accumulation of quantities, such as areas under a curve, linear distance traveled, or volume displaced.
These two processes act inversely to each other, as shown by the fundamental theorem of calculus.