Class: A class is a user defined data type with set of data members & member functions
Object: Object refers to the memory address of the class.
Reference: A reference is just like a pointer pointing to an object.
Instance: This represents the values of data members of a class at a particular time or Instance refers to the copy of the object at a particular time.
Object: Object refers to the memory address of the class.
Reference: A reference is just like a pointer pointing to an object.
Instance: This represents the values of data members of a class at a particular time or Instance refers to the copy of the object at a particular time.