Integration is an operation in mathematics, just as we do addition, subtraction, multiplication, division etc.

In general, concepts in physics, like area, volume, displacement etc. represented graphically uses the concept of integration. Any curve represented in a graph indicates variation of the function with respect to change in value of x. For example, F(x) varies as a function of x. 

Just as we have multiplication and division, the fundamental concept of calculus, considers differentiation and integration as inverse of each other.

If we need to find the area of region under the curve, we divide the entire area into smaller area strips. The summation of area of all such strips forms the area under consideration. The integration operation helps to achieve this easily. 

With the help of boundary conditions depending upon the maximum and minimum value x can take, we can give limit values to the integration function.

y = ∫ f(x) dx represents an integration function and ∫ represents the symbol for integration.