Calculus is a central branch of mathematics, developed from algebra and geometry, and built on two major complementary ideas.
One concept is differential calculus. It studies rates of change, which are usually illustrated by the slope of a line. Differential calculus is based on the problem of finding the instantaneous rate of change of one quantity relative to another.
The other key concept is integral calculus. It studies the accumulation of quantities, such as areas under a curve, linear distance traveled, or volume displaced.
(From Wikipedia, the free encyclopedia.)
