Virtualisation within virtualisation?
"Containerisation is, if you will, almost like virtualisation within virtualisation."
It's also almost like an OS that works, keeping processes (and data) apart when the owner of the machine doesn't want them to trample on each other. I think the idea was invented in the fifties and the only reason anyone can still sell it as "the next great thing" is because consumers have had such utter crap foisted on them in recent decades, so hardly anyone under the age of 50 can remember using a computer system that lets *you* control who sees and uses your data (and hardware, for that matter).
(Icon: "crusty old fart" rather than "Windows user", although I'd be the first to point out that Mr Cutler's fine offering is an example of an OS that worked that has, over the years, been dumbed down in the name of usability to the point where it no longer does the one job that would be useful.)