This document discusses design patterns including the provider pattern. It begins by listing some object-oriented programming principles and software architecture patterns. It then focuses on the open-closed principle and how the provider pattern adheres to this principle by allowing new types to be added without modifying existing code. The provider pattern works by dynamically creating instances of classes based on external configuration settings, avoiding the need to modify code. This is compared to the factory pattern, which still requires in-code configuration and modification. Real-world examples of implementing the provider pattern are also provided.