You should know that integration is a calculus operation and it is the reverse process of dfferentiation.
You may also call integration process as finding the antiderivative of the function.
The process of evaluation of definite integral of a function means the process of finding the area between the graph of the function and x axis.
You need to know two methods of integration, at least, such that: integration by parts and integration using substitution.
You should remember the formula used by the method of integration called integration by parts:
int udv = u*v - int vdu
You may use the method of integration by substitution when the integrand consists of a function and its derivative.
You may also use definite integral to evaluate the volumes of solids of revolution.