Mutable Objects and Immutable Objects are both created or built-in classes in Java. To distinguish these classes we will rely on the characteristics as well as the behavior of that object using Getter/Setter methods.
Mutable Object: When we initialize one object, we can refero an instance of a class, the state can be changed after successfully object initialization.
Immutable Object: When we initialize one object, the state of the object cannot be changed after successfully object initialization.