getGradeLevel method:The getGradeLevel method retrieves or gets the current grade level attribute or property of an object. It returns the existing grade level associated with that particular object.
inheritance: Inheritance is a concept in object-oriented programming where one class inherits properties and methods from another class. It allows for code reuse and creating hierarchical relationships between classes.
encapsulation: Encapsulation is one of the four fundamental principles of object-oriented programming (OOP). It refers to bundling data (attributes) and methods (functions) together within a class, hiding internal details from outside access.