what is integration?

Well,there is different meaning of integration in different fields . But here i am assuming that you are asking related calculus??So i,will stick to that only . SO,firstly it  defines only the area inside curve .It is denoted as  (∫) over some interval,in the calculation for area . There are some types of integration as well . Well some basic types are definite and indefinite integral.So ,in indefinite integral,we have to only integrate , the function with respect to some variable,we get some constant as well after integrating,while in definite integral we integrate the function over some interval,so it is helpful to calculate the area as well ,While in definite integral,we actually get the correct answer without any constant of integration.This is the main difference between indefinite and definite integration .While,we can have different correct answers in case of indefinite integration , on the other hand ,we have only one correct answer for definite integration .Now there is some sub-types of integration which you will face like:-substitution,trignometric,partial fraction,improper integrals,integration by parts,sin/cosine function an many more ...