The integral calculus is the part of “the” calculus that deals with integrals—both the integral as the limit of a sum and the integral as the antiderivative of a function (see below for more information). In general, the integral calculus is the limit of a sum of elements in which the number of the elements increase without bound, while the size of the elements diminishes. It is also considered the second most important kind of limit in the calculus (the first being limits in association with derivatives). It was originally developed by using polygons to approximate areas of geometrically shaped objects such as circles.