Technically, containers running on MacOS and Windows are a (Linux) VM, under the hood. Now, Microsoft put in a lot of work to support something like namespaces in the Windows kernel, so that it's now possible to run "Windows-native containers" for Windows software. But both Windows and MacOS still use a Linux VM under the hood to run Linux containers. That being said, I'm not familiar with the details of Windows containers because I don't use any Windows software and therefore don't have a reason to run any Windows containers. If you are interested in how containers work at a lower level, you might get more out of the documentation for containerd and runc, which are the underlying container runtimes.