what is the use of class in c++?

Answer 1

Object oriented stuff = encapsulation = more secure code = code reusability = managing large projects easily = maintaining more easily = dividing project modules easily between team members = ....

Heart of all of them is class.

Answer 2

class is the way of implementing oops concept like encapsulation, data hiding, data abstraction, inheritance etc. c++ is the extended version of C, with additional features of language simula 67.simula 67 was one of the earliest object oriented languages. so classes are important part of c++.