"Design patterns are recurring solutions to software design problems you find again and again in real-world application development. Design patterns are about design and interaction of objects, as well as providing a communication platform concerning elegant, reusable solutions to commonly encountered programming challenges.
The Gang of Four (GOF) patterns are generally considered the foundation for all other patterns. They are categorized in three groups: Creational, Structural, and Behavioral. Here you will find information on these patterns together with downloadable source code in C#.
To give you a head start, the source code is provided in two forms: structural and real-world. Structural code uses type names as defined in the pattern definition and UML diagrams. Real-world code provides real-world programming situations where you may use the patterns. "