Guide to how the security features work

Hi,

Trying to find some documentation on how the security features work but the user guide doesn't mention them at all.

I would like to know where the updates brought down for updating one pc are held after the update is applied. Is there a repository held on the central server or on each probe so that the same update is downloaded over and over again for each PC? If so, where?

Also, how do you schedule when the updates are applied? Is it the "schedule settings" tab on the left?

3rdly, when I tested applying updates to a PC, it did a reboot at the end. How do I control this? I don't want servers rebooting without me knowing. How do I know what updates will force a reboot?

Cheers,

Simon