What is the fundamental principle of polymorphism in Java?

The main principle of Java polymorphism is method overriding and dynamic binding.

Method overriding refers to a subclass being able to rewrite a method in the parent class, with the subclass method having the same name, parameter list, and return type as the parent class method. By using the @Override keyword to indicate that the method is overriding a parent class method, this ensures that during compilation it is checked whether the parent class method has been correctly overridden.

Dynamic binding is the process where the Java virtual machine determines which version of a method to call based on the actual type of the object during runtime. This dynamic selection process is known as dynamic binding or runtime binding.

Java achieves polymorphism through method overriding and dynamic binding. Polymorphism allows for greater flexibility and scalability in a program by enabling a parent class reference to point to a child class object, thus extending the program’s functionality without altering the existing code.