What Is Middleware?
At its core, middleware is software that lies between the operating system or database and applications. In the context of web frameworks, middleware typically refers to functions or components that process incoming HTTP requests before they reach your application’s final request handler (or process outgoing responses after they leave your handler).
Key characteristics of middleware include:
- Sequential Processing: Middleware functions are often arranged in a chain. Each function gets an opportunity to examine or modify the request and response objects.
- Decoupling: Middleware allows you to separate concerns such as logging, authentication, error handling, and data parsing from your core business logic.
- Reusability: Middleware components can be reused across different routes or applications, ensuring consistency and reducing code duplication.