Newbie question : difference between « SteamVR » and « WaveVR » plugins


I’m just beginning to learn to use UE4 to try of a very simple APK for VR.

This seems like a very newbie question, but I would like to know (and to understand) the difference between the « SteamVR plugin » and the « WaveVR plugin » for Unreal.

I’m not sur that the former allows to use VRMode (preview mode) and the latter to package suitable APK for the Focus 3.

Is that correct ?

Thanks for return.