Design patterns are reusable solutions to common problems in software design. They provide a template for how to solve a problem in a way that has been proven effective over time. By using design patterns, developers can improve code readability and maintainability, making it easier to manage complex systems. There are several types of design patterns, including Creational, Structural, and Behavioral patterns. Each type addresses different aspects of software design, helping developers to create more efficient and scalable applications. Understanding these patterns can significantly enhance a developer's ability to write high-quality code.