Design Patterns are proven, reusable solutions to common problems that occur while designing software systems . A Design Pattern is: Why Design Patterns Are Important Categories (Types) of Design Patterns Design patterns are mainly divided into three major categories 1. Creational Design Patterns Instead of creating objects directly, these patterns control how objects are created. 2. Structural Design Patterns 3.Behavioral Design Patterns Behavioral design pattern Focus on communication between objects. They define how objects interact and share responsibilities. Behavioral patterns are Example: Create objects from one central place. Client does NOT know how objects are created. 1. Create Interface 2. Create Classes 3. Factory Class 4.Client Code