Mutator Method: A mutator method, also known as a setter method, is another public method in Java that allows modification or update of the value of an instance variable. It provides indirect access to private variables by allowing them to be changed.
Instance Variable: An instance variable is a variable declared in a class and each object or instance created from that class will have its own copy of that variable.
Encapsulation: Encapsulation is one of the four fundamental principles in object-oriented programming. It refers to bundling data and methods together within a class and controlling access to them through encapsulation mechanisms such as private variables and accessor/mutator methods.