The Ultimate Character Controller is the parent asset for a set of child assets. At their core each asset shares base functionality which is then extended based on the imported asset. The Ultimate Character Controller supports switching between first and third person perspective in addition to supporting a wide variety of items. If you have UFPS or the Third Person Controller then only one perspective is supported while all of the items are supported. If at any point you’d like to add support for a different perspective in your game you can import the asset which adds that functionality.
The API for the character controller can be found using the Object Browser of your IDE. We are using the Object Browser for API documentation because it is always up to date for the current version that you are using. It also is interactive so it easy to navigate through the API.
If the Object Browser does not generate the documentation for the classes you can regenerate the project file from the Unity Preferences: