The Decorator Design Pattern is a structural pattern used to dynamically add behavior or responsibilities to objects without modifying their existing code. It provides a flexible alternative to subclassing for extending functionality. Key Concepts: Component (Interface or Abstract Class): Defines the common methods that both concrete and decorated objects must implement. Concrete Component: The base class that implements the component interface. Decorator (Abstract Class): Holds a reference to the component and extends its behavior. Concrete Decorator: Adds additional functionality to the component dynamically.