In this section, we will learn how to implement user authentication in our Angular applications.

User authentication, in a broad context, consists of safely logging the user into our application, who should be able to view, edit, and create data on secure pages, and finally, log out of the application!

In a real-world application, there will be a lot of additional checks and security implementations to be done to sanitize user inputs, as well as checking whether they're a valid user, or verifying the authentication token for session timeouts, and other data checks to make sure no bad elements creep into the app.

The following are some important modules for user authentication:

• Signing up new users
• Login for existing users
• Password reset
• Session management for logged-in users
• One-time password or dual authentication
• Logging out an already logged in user

In the upcoming sections, we will learn about implementing the preceding functionality using the Firebase and Auth0 frameworks.