Sorry if the question has already been answered, but I couldn't find it.

I upgraded from 7.1 to 7.2.1 because in the administration console I read that the upgrade was critical, but after the upgrade and also before, there was also the upgrade to 8.0.0 outlined as critical.
I don't think so, but I don't know, so I ask.
And how can I do to know when an upgrade is really critical and instead when is only the interface of the admninistration console that thinks so?
Where can I find usually such information?

Best regards to everyone and thanks to replying people,