The difference between Classes Objects and Instances

Question

As the title says, what is the difference among them in Java?

Answer 1

A class is a type of blueprint that you can use to make objects. A concrete 'thing' that you constructed using a certain class is an object, which is an instance of a class. So, while the terms 'object' and 'instance' are interchangeable, the term 'instance' refers to an object's relationship to its class.

If you look at an example, you'll see what I mean. Let's say you have a class called House. This is an object that belongs to the House class. Another object is your sister's residence (another instance of class House).

// Class House describes what a house is
class House {
    // ...
}

// You can use class House to create objects (instances of class House)
House myHouse = new House();
House sistersresidence = new House();

The class House defines what a house is, and there are specific, concrete houses that are objects and instances of this class.