Raspberry Pi Zero

Hello, I am a Raspberry neophyte. I would like to know if the Pi Zero plays H265 and
4K videos.

No, the Pi Zero can not play either of the 2.

  1. Only the Pi 4 can technically output 4k and has a H265 hardware decoder
  2. Only the Pi3 is capable of software (CPU) decoding low resolution H265 decoded videos

I would add that the RPi 4 is not currently supported by OSMC, and the two operating systems that it does work on are still a bit rough around the edges, and do not currently support HDR output. Although the RPi 3 can decode in software some h.265 content I would submit that what it can play is limited enough that it should not be considered a viable option for this use. If you wanted a machine to play this kind of content a Vero 4K+ box would be a better option than any of the RPi’s currently.