Can you explain the concept of design patterns and provide examples of design patterns commonly used in JavaScript development?

Design patterns are reusable solutions to common problems in software design. In JavaScript, common patterns include the Singleton Pattern (ensuring a class has only one instance), Observer Pattern (defining a one-to-many dependency between objects), and Module Pattern (organizing code into independent, reusable units).

These patterns enhance code maintainability, scalability, and readability. For instance, the Observer Pattern is widely used in event handling, while the Module Pattern helps in organizing code into manageable pieces.