The built-in version for each major Unity release is based on a specific package version.
The built-in version of UI Toolkit includes the features required to make user interfaces for the Unity Editor. The package version contains additional features required to make runtime user interfaces for games and applications.
Both versions of UI Toolkit work the same way, and use the same namespaces:
UnityEngine.UIElements. If you install the package, you don’t need to do any additional configuration.
The decision of what version of UI Toolkit to use depends on the user interfaces you plan to make.
Installing the package also gives you access to the latest UI Toolkit features. Unity may release preview versions of the com.unity.ui package between major Unity releases.
|Preview versions of com.unity.ui might contain features that are not stable or final. Avoid using preview versions in production.|
You install the UI Toolkit package from the package manager:
The package manager automatically finds and installs the UI Toolkit package.