What is the difference between a class and an object?

Class vs object

A class is a blueprint (fields + methods). An object is a runtime instance of that class with its own state on the heap.

class Student { String name; int rollNo; }
Student s1 = new Student(); // object
s1.name = "Riya";

• Class exists once per classloader; many objects can be created with new.
• Static members belong to the class; instance members belong to each object.