Java OOPS Concept: Polymorphism (compile-time & run-time)

What is Polymorphism?

Polymorphism means "many forms" — the ability for the same method name to behave differently depending on context.

Compile-Time Polymorphism (Method Overloading)

Multiple methods share the same name but differ in parameters; the compiler decides which one to call based on the arguments provided.

int add(int a, int b) { return a + b; }
double add(double a, double b) { return a + b; }

Run-Time Polymorphism (Method Overriding)

A subclass provides its own implementation of a method already defined in its parent class; Java decides which version to run at runtime, based on the actual object type.