How does the filesystem setup work?

I’m curious as to how Nomad handles changes to the filesystem, I’m interested in contributing to a project which handles the filesystem in the kind of way that changes are stored separate from the base system as to me this sounds like a very reliable system; from what I can tell, Nomad is exactly this, is this correct? If anyone could provide me with some details to how the filesystem setup works, I’d love to hear about it! :smile: