What is Passport.js Middleware?
Passport.js is the middleware that has the functions that are executed during the request-handling tasks. Using this we can integrate different authentication strategies like local authentication using usernames and passwords, OAuth, OpenID, and more strategies. This middleware is integrated into the Express.js applications which allows us to define the route and enforce the authentication at each endpoint.
Explain the use of passport.js for authentication in Express applications.
Authentication is an important aspect of maintaining the overall security of the application. As Express.js is the server-side language, it is important to secure the application with authentication. So we can use Passport.js which is the authentication middleware that has a modular way to implement the authentication strategies which includes the OAuth, username/password, and more authentication features.