What is the purpose of inner classes in a program?

Inner (nested) classes in Java are used for logically grouping classes that are closely related and not intended to be used separately. They help:

• Improve encapsulation by hiding helper classes inside the outer class.
• Access private members of the outer class.
• Organize code more structurally, especially when the inner class is used only within the outer class.

Example:

class Outer {
    private int outerValue = 10;

    class Inner {
        void display() {
            System.out.println("Outer value is " + outerValue);
        }
    }
}