When you install Docker for Windows, that currently lets you run Docker Linux containers. Running Linux containers on Windows 10 is achieved technically by running a minimal Linux VM using Hyper-V. You can run many Linux Docker containers side by side this way, and they all share the same Linux VM, running on Windows.
When you run actual Docker Windows containers (which is not what you do when you install “Docker for Windows”), it’s what @andrewconnell said.