This sounds stupid but I was wondering what happens if u miss a VPS I missed VPS 522-3 but I got VPS 522-4 . Do I need to download it or not and if I do need to download it where . Thanks for your help.
Of course not ;D
The newer version always contains everything from the older version(s).
The upgrade are cumulative 
Thanks Vlk so I won’t worry about the old VPS 522-3 because the new one I just got will be has good has the new one I quess u r saying 522-4. So if I miss any for a week it will be okay if I leave my computer off.
Sure (except that you’ll be downloading slightly bigger file - but still relatively small).
Actually update are incrimental. avast! synchronizes with server and checks what you already have and what has been missed. Then it downloads all missed updates (this includes all missed+latest available).
Lets say you have update 0566-0 (just example version number)
Update 0566-1 (45KB in size) is missed
Update 0566-2 (6KB in size) is cought by avast! and updated → avast! will download 51KB of updates
This is ofcourse simplified description,but this is the way how it works.
Thanks for all your help now I understand it so I won’t worry while I go for a week on holidays. I will pick it up where I left off at and still be protected when I go back on line.
It’s actually a bit different, but the basic idea is the same.
Virus databases are labeled as XXXX-YY.
YY are always increments to YY=0.
I.e. 0566-1 is downloaded as an increment from 0566-0, 0566-2 is an increment from 0566-0 etc.
Then, there’s an increment from 0566-0 to 0567-0, 0567-0 to 0568-0.
XXXX is currently incremented once a week (on Monday, there’s usually VPS XXXX-0).
This scheme has proven to be most effective (otimal bandwidth usage).