Classes has the data and its associated function wrapped in it. Classes are also known as a collection of similar objects or objects of same type. In the OOPs concept the variables declared inside a class are known as "Data Members" and the functions are known as "Member Functions".

   class class-name
    {
      private:
          variable declaration;
          function declaration;
      public:
          variable declaration;
          function declaration;

    };

#include <iostream.h>
class Square
  {
     public:
        int area( side)
          { 
            a =side*side;
            return a; 
          }
     void show()
     {cout << "The area is::" << a;}
    private:
      int side, a;
  }x;
void main()
 {
      Square x;
      x.area(10);
      x.show();
 }

    The area is:: 100

In the above OOPs example the class "square" has functions "area" and "show" to calculate the area of the square and to display the area. so all these are objects that are related to the class "Square".