There is the idea of "high level concepts", concepts that build on top of other concepts. So it's probably impossible to explain without some insight knowledge

There is the idea of "high level concepts", concepts that build on top of other concepts. So it's probably impossible to explain without some insight knowledge into operating systems, programming, multi processing, security, packaging, CS history, etc. Explaining it to undergrads would therefore require a "model", i.e. an abstraction of the reality that simplifies what is really there, but is still apllicable to make predictions about outcomes in the real world. So I would start with analysing how I would explain unix user management to a newby who didn't learn filesystems yet. Then transfer some of that thinking to processes instead of files. E.g. this process doing X and that process doing Y shouldn't conflict with each other but might get problems when they both try Z. Therefore they need to be separated in an abstract way. And that's what namespaces are for. yadda yadda. Another approach might be taking ideas from explaining virtual memory to newbies. I.e. each process has their own virtual filesystem, their own virtual network, and the underlying operating system will figure out how to make things work out without conflicts (if possible).