Apple 4K TV vs Vudu

[TitusTroy]

I'm not sure if this the right place to post this but I'll give it a shot...I currently have an LG C7 OLED (with Dolby Vision support)...is there a difference in UHD/HDR picture quality from using the LG C7's built in Vudu app versus something like an Apple 4K device when streaming movies?

I keep seeing people rave about Apple 4K (iTunes) but I don't understand...do they use more bitrates in their UHD streams?...is the quality that much better?...what about something like FandangoNow vs Vudu (using the LG apps)?...I always thought streaming quality was generally the same (of course UHD Blu-ray quality is much better)

I've never used Apple TV before and was thinking about picking one up if the difference in quality is much better then LG's built in streaming movie apps