Updating (apt update etc) of the main machine - how to do it right?

Question

KVM

Hello!
I want to try KVM and create 5-7 test virtual servers (of course, the server will be real :)
all are planned ubuntu server The
question is actually this - the host system (hypervisor) is planned to be updated with apt update, etc., but what about virtual machines?
they will be those versions and states that were at the time of their installation, right?
How then to do the right thing so that all guest OSes have up-to-date updates?
How is this issue resolved at the level of hosting providers where the number of guest OS reaches thousands?
Or are guest systems a headache for its owner and it is enough to keep only the hypervisor up to date?

Answer 1

If you mean VPS - this is the problem of the one who shoots it - anything can be there, even Windows :)