This tutorial provides a step-by-step guide to integrating Facebook login into a Node.js application using Passport.js, a popular authentication middleware for Node.js. The project uses the MVC (Model View Controller) pattern and is set up with MongoDB as the database. To get started, developers need to create a Facebook developer account, install the necessary dependencies, including Passport and Passport-Facebook, and configure their application's callback URL. Once configured, users can authenticate with Facebook by visiting a specific URL, entering their credentials, and being redirected back to the application upon successful validation. The application then exchanges the authorization code for an access token, which is used to request resources from the resource server. The tutorial concludes by providing a working project example and encouraging developers to try implementing Facebook authentication in their own applications.