Ray Tracing Overview - Unreal Engine 4.22 Preview

I am confused about Raytracing and Baking and considering Lightmass?

When I am going to Raytrace GI, AO, Reflections and Refractions (Translucency)… well… do I still need to bake and build the light?
And do I still have to consider Lightmass when using Raytracing? Or can I forget about it?

Thank you so much for bringing light into the darkness