A check for new software will occur every night at 1AM. If a new version is found, it is downloaded and installed automatically, without user input.
If the backup client is not running at that time (ie: your computer is turned off), the software will check for updates automatically the next time it is started.
When you start the backup client, and a new update is found, a notification will be presented to you in a screen title “New update available”.
This allows you to start the backup manually, after which the backup client will start up normally.