In this chapter, we covered the basics of authenticating the identity of our users and granting them access to certain pages based upon attributes we set in the user identity interface, and how to implement Yii2's hierarchical role-based authentication. We also explored how to use flash messages to enhance our user experience. Additionally, we explored a few components of the security component, which enabled us to hash the user's passwords, hash and verify data, and encrypt and decrypt information utilizing the user's password.
In the next chapter, we'll cover more complex routing within our application, how to work with and modify our responses directly with Yii2, and the basics of listening and responding to events.