The `Auth` class provides a common interface to authenticate user credentials from different
sources against different storage backends in a uniform way. As with most other adapter-driven
classes in the framework, `Auth` allows you to specify one or more named configurations,
including an adapter, which can be referenced by name in your application.
`Auth` is responsible for managing session state for each configuration, and exposes a set of
methods which adapters can implement: `set()`, `check()` and `clear()`. You can read more about
each method below. Beyond these methods, `Auth` makes very few assumptions about how your
application authenticates users. Each adapter accepts a set of credentials, and returns an array
of user information on success, and `false` on failure. On successful authentication attempts,
the data returned from the credential check is written to the session, which is automatically
accessed on subsequent checks (though manual re-checking can be forced on a per-instance basis).
For additional information on configuring and working with `Auth`, see the `Form` adapter.