Docker uses container functionality specific to the Linux kernel. So on Linux, you can install a relatively lightweight engine. But on MacOS or Windows, you need to install the entire "Docker Desktop" app, which secretly spins up a Linux VM in the background, and presents a (pretty poor) abstraction as if this is all running on the host machine.
On Windows, you don't really need to use Docker Desktop, I personally find it more convenient to run just plain old Docker in WSL. It's still a Linux VM, but you get more control over it.
I never understood what the point of Docker Desktop was on Windows if WSL exists.
docker-machine from brew sets up the linux vm using one of a few virtualization options. iirc I always used bhyve and never had to give it a second thought.
