Lesson 1	Introduction to Structural Design Patterns
Objective	Explain the role of structural design patterns and their importance in organizing complex systems.

Structural Design Patterns

Structural design patterns describe proven ways to compose classes and objects into larger structures while keeping systems flexible, reusable, and efficient. These patterns are especially valuable when software must evolve over time, allowing components to be adapted or extended without breaking existing functionality.

What You Will Learn

The purpose and role of structural design patterns
Key characteristics of the seven GoF structural patterns
How patterns like Adapter, Facade, and Proxy simplify system organization
When patterns such as Flyweight are effective (and when they are not)
How these patterns apply to real-world applications and the course project

How Structural Patterns Work

The central idea behind structural patterns is composition—arranging objects and classes so they can be safely combined, reused across contexts, and modified with minimal impact. For example:

Adapter connects incompatible interfaces so they can work together.
Composite organizes objects into tree structures for flexible hierarchies.
Facade provides a simple, unified interface to complex subsystems.
Proxy acts as a placeholder to control access, caching, or security.

How They Differ from Other Patterns

Unlike creational patterns (which focus on object instantiation) or behavioral patterns (which manage communication and responsibility), structural patterns deal with the organization of code. They define how components connect and cooperate to build larger systems that remain maintainable as requirements change.

Conclusion

Mastering structural patterns equips developers with strategies to manage complexity in modern systems—from user interface toolkits to distributed applications. By applying these patterns, you create software that balances flexibility with clarity, making it easier to scale and maintain over time.