CHAPTER 14 Authentication and Authorization Authentication and authorization are two very related, and yet separate, concepts. While the former deals with identifying a user, the latter determines what a user is allowed to do. Unfortunately, since both terms are often abbreviated as "auth," the concepts are often conflated. Yesod provides built-in support for a number of third-party authentication systems, such as OpenID, BrowserID, and OAuth. These are systems where your application trusts some external system for validating a user's credentials. Additionally, there is support for more commonly used username/password and email/password systems. The former route ensures simplicity for users (no new passwords to remember) and implementors (no need to deal with an entire security architecture), while the latter