Reuses code and promotes hierarchical organization.

• The method in the subclass must have the same name, return type, and parameters as the method in the superclass.

• The method must be inheritable, i.e., not marked as private or final.

• Members declared public are accessible from anywhere, including outside the package.

• Accessible within the same package and also from subclasses (even in different packages).

• Accessible only within the same package.

• Not accessible outside the class, including from subclasses.

• A subclass can access public and protected members of its superclass, but not private members.

• Each class must define its own constructors, even if it's a subclass.

• Used to explicitly call a constructor from the superclass.

• If not called, Java inserts a default super() call to the no-arg constructor of the superclass.

• If the superclass does not have a no-arg constructor, the subclass must explicitly call a constructor with parameters.

• At compile-time, the reference type determines which methods are available.

• At runtime, the actual object type determines which method is executed.

• Supports extensibility and flexibility in code.

• Makes it easy to introduce new classes with minimal changes to existing code.