No application can be built without including some kind of authentication/authorization mechanism, and Firebase applications are no exception. Hence, Firebase provides us with many options for authenticating users as follows:
Custom: This is for complete control over authentication. This requires server-side code and by using it we can generate our own login tokens.
E-mail and password: We can register and authenticate users using e-mail and password.
Anonymous: For small one-off tasks, we can use anonymous authentication where users are not required to register with us. A unique identifier is generated for each user that lasts as long as their session.
OAuth providers for Facebook, Twitter, Google, and GitHub: We can authenticate users using any of these OAuth providers.
We have to configure each provider individually and enable it in the Firebase dashboard before any of the clients can use it. Please check AngularFire Development Guide (https://www.firebase.com/docs/web/libraries...