Constant Variable: A constant variable is declared using the final keyword and represents fixed values that cannot be modified during program execution. They are typically used for storing values that should not change throughout the program.
Immutable Object: An immutable object is an object whose state cannot be modified after it is created. The final keyword is often used to create immutable objects by making their fields private and final, and not providing any setter methods.
Final Method: A final method is a method that cannot be overridden by subclasses. Once a method is declared as final in the superclass, it cannot be modified or overridden in any of its subclasses.