How is the mechanism of polymorphism achieved in Java?

In Java, polymorphism is achieved through inheritance and interface implementation, allowing objects of different classes to be processed through a common type. The main mechanisms:

• Method overloading (compile-time polymorphism) — methods with the same name but different parameters.
• Method overriding (runtime polymorphism) — a subclass overrides a superclass method, and the method call is determined at runtime.

Example:

class Animal {
    void sound() {
        System.out.println("Some sound");
    }
}

class Dog extends Animal {
    @Override
    void sound() {
        System.out.println("Bark");
    }
}

public class Main {
    public static void main(String[] args) {
        Animal animal = new Dog();
        animal.sound(); // Will output "Bark" thanks to polymorphism
    }
}