Live updates are usually found in programs that are connected to the Internet and would like to transmit data back and forth.  The most useful feature of live updates include the capability to update your software.

Live updates are more commonly referred when talking about Norton Anti-virus.  Norton Anti-virus contains a feature that will allow you to update your virus definitions so you will be protected by the latest anti-viruses at all times.  Norton Anti-virus connects to the Symantec website and checks to see if you are up-to-date and if you're not, they will have them ready to be downloaded to your computer at your command (or you may have your software set for automatic downloads.

Many programs feature Live Updates but may have a different name, but this will give you an idea what that techie who fixes your virus problems is talking about.