Trying to understand unused port blocking in the Norton products

Norton Security | Norton Internet Security
1

I use NAV2008 which has the inbound "firewall"

I know it works because i frequently get the following type of message

 

Unused port blocking has blocked communications.
Inbound TCP connection.
Remote address,local service is 82.56.81.14,   80.

 

where I assume 80 is the port number

 

So NAV2008 blocked an inbound to port 80?  isn't the port 80 needed for accessing the internet?