Linux 101 stuff. Questions are encouraged, noobs are welcome!

I will try to put it simply

1. the linux kernel provides the hardware compatibility in a general sense.
2. Then the driver for your specific card is coming as a kernel module, in your case amdgpu, which is the open-source driver that works very well, but amdgpu-pro is the proprietary driver from AMD and most NVidia users will also install the proprietary module.
3. Finally you have libraries implementing APIs to OpenGL, Vulkan, video decoding, etc. All of those are bundled in software packages, that depend on your distro. In your case you can most certainly install a MESA package that will give you everything you need, compatible with the Kernel you have.

In summary, drivers come in 3 parts: Linux kernel, kernel module, libraries. Usually you install a driver that provide you the module and libraries compatible with the kernel. You rarely have to worry where they exist on the filesystem, and nowdays most distro will automatically detect and install what you need.

Ok, no that simple in the end 😅

Refer to the other comment for where it is. The release cycle depends on your distro. If you use arch, you'll always get the latest stuff as it releases. That's the thing that makes arch a good choice for gaming.

Other distros are generally more delayed or only release major versions that don't break anything.

For nvidia this means you have specialized distros created for the sole purpose of having a working nvidia driver that come in different versions because even the 'stable' versions aren't very stable. With AMD, you basically don't need to worry.

It's a mix of mostly (using Arch Linux package names here) mesa, vulkan-radeon, linux-firmware and linux (in particular the amdgpu module). Your package manager should update all of these for you when prompted and updates are available.

I personally use an Nvidia card, so someone more knowledgeable can correct me.

For the open source drivers, Its a combination of both an AMDGPU (newer cards) or ATI (older cards) kernel module, alongside the mesa package, which provides 3D acceleration and OpenGL support. There is a separate package for Vulkan support too, either vulkan-radeon or amdvlk. For hardware video decoding, there is libva-mesa for VA-API, and mesa-vdpau for VDPAU support.

So yeah, Windows has one monolithic drivers .exe, and Linux has it all split out into separate chunks. How quickly you get updates depends on your choice of linux distro.