: While authoritative, some modern reviewers find it dense. Beginners often recommend starting with Head First Design Patterns on Quora as a more approachable introduction before diving into the GoF original.

How classes and objects are composed to form larger structures. Adapter, Decorator , Bridge How objects communicate and distribute responsibility. Strategy, Observer, Command Reader Perspectives

The book organizes patterns into three main "chapters" or categories based on their purpose: Key Examples Ways to create objects while hiding the creation logic. Factory Method , Singleton , Builder Structural