final keyword when used with method results in final method, which cannot be overridden in subclass. final keyword is used to restrict user.
final keyword is also used with class and variable.
final method can be declared as:
public final String convertCurrency()
public class FinalDemo
public final void display()
System.out.println("In class FinalDemo");
class A extends FinalDemo
public void display() // Error Final method cannot be overridden