Could you explain what is meant by Middleware and what role it plays in system architecture?

Middleware is a software component that sits between two other components of a system and processes requests or data passing through it. In application architecture, especially in web development with Node.js, middleware are functions that receive the request object, response, and the next function in the chain, and can perform operations such as authentication, logging, error handling, request body parsing, etc.

The role of middleware is to divide request processing logic into separate, reusable parts, simplifying the application's structure and ensuring sequential data processing.

Example of middleware in Express.js:

app.use((req, res, next) => {
  console.log(`${req.method} ${req.url}`);
  next(); // pass control to the next middleware
});