EMF Forms is a component of the EMF Client Platform project that provides a form-based User Interface to display and edit your data, a.k.a. the entities of your application. The UI is rendered based on a view model at runtime and provides an out-of-the-box experience while being highly customizable. If you are not familiar with EMF Forms yet, please read this tutorial.
We have just updated the documentation with more information how rendering in EMF Forms works in the 1.3 release with details on prioritization, styling and layouts and how they can be influenced and customized. The new documentation can be found here.