The integral symbol is used to represent the integral operator in calculus. Typically, the integral symbol is used in an expression like the one below.
In plain language, this means take the integral of the function with respect to the variable from to . See integral notation for typesetting and more.
An integral can be geometrically interpreted as the area under the curve of a function between the two points a and b. Integrals are a core operator in calculus and are used throughout physics and higher-level mathematics.