A common question in Java OOPS coding questions and answers, don't miss this one. The Decorator design pattern is based on the concept of inheritance. This pattern allows you to extend the functionality of an existing object without having to modify the code of the original object. The new functionality is added by creating a new object that wraps the original object. The new object has the same interface as the original object, but it also includes the new functionality. This allows you to seamlessly add new features to an existing object without breaking compatibility with existing code. The Decorator design pattern is a versatile and powerful tool that can be used to great effect in a wide range of situations.