Question

What is class in c++ and all types of classes?

Answer 1

A class in C++ is a user defined type or data structure declared with keyword class that has data and functions (also called methods) as its members whose access is governed by the three access specifiers private, protected or public (by default access to members of a class is private).

Answer 2

Class is a collection of data member and member function. Class is ah user define data type. Object is a class type variable. Objects are also called instance of the class. Each objectcontains all members(variables and functions) declared in the class
A POD-struct (Plain Old Data Structure) is an aggregate class that has no non-static data members of type non-POD-struct,non-POD-union (or array of such types) or reference, and has no user-defined assignment operator and no user-defined destructor. APOD-struct could be said to be the C++ equivalent of a C struct