What is the purpose of middleware in web applications?

Middleware serves as a bridge between different components of a web application, often positioned between the client-side and server-side processes. Its primary role is to process requests and responses, thereby adding additional functionalities such as authentication, logging, session management, and more. Middleware can intercept requests before they reach the actual endpoint, enabling developers to implement cross-cutting concerns in a modular fashion. This means that common tasks like handling sessions and managing user authentication can be managed efficiently without repeating code across multiple routes or handlers. By using middleware, developers can ensure that these functionalities are applied uniformly throughout the application, leading to cleaner and more maintainable code.

The other options each focus on specific areas of application development rather than the broader role that middleware plays in connecting various components and enhancing functionality.