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Difference Between Router and Middleware in Express.js

In Express.js, a router and middleware serve different purposes in handling HTTP requests.

Router in Express.js:

A router in Express.js is used to define a set of routes for different HTTP methods and URIs. Routers help in modularizing the application's routes into separate entities, allowing for better organization and maintainability of the code.

Middleware in Express.js:

Middlewares in Express.js are functions that have access to the request and response objects, and the next middleware function in the application's request-response cycle. They can perform tasks such as logging, validation, authentication, etc., before passing the control to the next middleware function.

Main Difference:

The main difference between a router and middleware in Express.js is that routers handle routing and define the application's routes, while middlewares are functions that execute tasks within the request-response cycle.

It is common to use both routers and middlewares in an Express.js application to define routes and add auxiliary functionalities to the request-handling process.

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