Inheritance and Extended Classes

• Extended classes are also known as subclasses.
  
• Inheritance models the is-a relationship.
  
• If class E is an extended class of class B, then any object of E can act-as an object of B.
• Only single inheritance is allowed among classes.
• All public and protected members of a super class are accessible in the extended classes.
• All protected members are also accessible within the package.