Integrals also refer to the concept of an antiderivative, a function whose derivative is the given function in this case, they are also called indefinite integrals.

Conventionally, areas above the horizontal axis of the plane are positive while areas below are negative. The integrals depicted here are called definite integrals, which can be interpreted as the signed area of the region in the plane that is bounded by the graph of a given function between two points in the real line. Today integration is used in a wide variety of scientific fields. Integration started as a method to solve problems in mathematics and physics, such as finding the area under a curve, or determining displacement from velocity. Integration, the process of computing an integral, is one of the two fundamental operations of calculus, the other being differentiation. In mathematics, an integral is the continuous analog of a sum, which is used to calculate areas, volumes, and their generalizations.