Explain the concept of composition and how it relates to design patterns.

Composition is a fundamental concept in software design patterns that involves building complex objects or structures by combining simpler objects or components. It is a way to create relationships between objects where one object contains or owns another object, forming a part-whole relationship.

In composition, objects are organized in a hierarchical manner, with the composed object being responsible for managing the lifecycle and behavior of its component objects. This allows for creating flexible and modular designs, as components can be easily added, removed, or replaced without affecting the overall structure.

Composition is closely related to several design patterns, such as the Composite pattern, which is used to represent part-whole hierarchies. The Composite pattern allows clients to treat individual objects and compositions of objects uniformly, enabling recursive processing of complex structures.

Another design pattern that utilizes composition is the Decorator pattern, which enhances the functionality of an object dynamically by wrapping it with additional behavior. The Decorator pattern follows the principle of composition over inheritance, as it allows for adding new behavior to objects at runtime without modifying their underlying classes.

Composition is also a key principle in the SOLID design principles, particularly the Dependency Inversion Principle (DIP). DIP states that high-level modules should not depend on low-level modules, but both should depend on abstractions. By using composition and relying on abstractions, software designs become more flexible, maintainable, and easier to extend.

In summary, composition is a concept in software design patterns that involves combining simpler objects or components to create complex structures. It enables flexible and modular designs, supports recursive processing, and is utilized in various design patterns such as Composite and Decorator. Composition also aligns with the SOLID design principles, particularly the Dependency Inversion Principle.