What is the role and info of /dev/nvidia** devices on Linux?

I am using GeForce Titan XP on Ubuntu 18.04.

When I checked the /dev directory, I could see the various nvidia devices.

nvidia0, nvidia-modeset, nvidiactl, nvidia-uvm, nvidia-uvm-tools…

I want to know about the information and role of these devices.

Please let me know. Thank you.