Hello,
I know that you can download the latest VPS but say somebody has for example 0610-0, and the latest was/is 0613-1. Would it update all of the definitions from the past VPS versions? Such as 0611-1?
Updates are incremental, during update procedure are performed all changes between installed version of VPS database and latest available VPS, so database of definitions is same after update from for example 0610-0 and after brand new installation of whole VPS database from http://www.avast.com/iavs4pro/vpsupd.exe file.
Then it should update completely so you will have all of the updates released? Then how does the file manage to be so small?
Yes. No need to get partial updates or worry when you let the computer off for some days…
New update brings you up-to-date 8)
Again, the incremental process could do it.
Surprised? Well, this is avast 
Thank you everyone :). Now I know that if I download an update when I have VPS 0611-0 and the latest is 0612-2 I will get all of the updates that came out in between. Thank you!
If you go off on holiday and come back say two weeks later you will have probably missed about 8 VPS updates on average each update is about 10kb even if it were 20kb you are still talking about 80kb - 160kb update when you come back. I love avasts incremental updates, especially on dial-up.
That is one of the great features of avast!