What questions are asked during the update or upgrade process? It would be good to know beforehand in case we choose the wrong option when asked and there is no turning back.
I don't know if you're talking about a normal upgrade, which you do about once a week - perhaps more often, or an upgrade from one major version to another, but the answer is the same for both:
There are some, rare, cases (in both upgrades and release-upgrades), where a service or a post-install script will ask something, examples for this are
There also can be cases where you need to decide whether to keep an old configuration file or replace it with a new one. You will be asked to either replace, keep or compare, in any case - if you didn't change a configuration file manually, it's normally safe to replace it with the new one.
If a question is asked of you, and you really don't know what to do, just hit enter (or