So it recive updates .....
do you mean virus definition updates or anything else?
It also controls the avast shields (it is the main avast process), for instance the web shield and email shield, both of which have an on-line protection task to fulfil and run under avastSvc.exe (Avast Service).
if I don't use web shield and email shield does it still need internet connection?
Is i t ok if I allow avastsvc.exe, instup.exe, aswidsagenta.exe, AvEmUpdate.exe and overseer.exe outgoing only connection? or any of these also needs to have incoming??