I need little explanation about class object and instance. What i read is " class is user defined data type , classes are blueprints of objects. Object is entity which contains data its related methods. What is instance
You read correct, class is just a user defined data type or blueprint of objects. It does not occupy any memory. It just defines what the objects would be, what data it would contain and how will it behave. Where as objects and physical entities, it occupies memory. You create an instance of a class by using "new" operator
Box b = new Box();
Here b is a new instance of Class Box, it will have behavior specified by Box class. A Class does not have physical existence in it self, its a blueprint from which you can create any number of instances of that class.