LAN:
IEEE - not too large area, 
       not too many users,
       not too low bandwidth,
       share the same media
Strict Definition -
   Two machines can communicate
   directly without going through
   a layer 3 device

WAN: 
Strict definition -
   Any network beyond LAN
Common definition -
   Networks that uses WAN technologies
   (usually supplied by ISP) 

HTTP://www.google.com
(0) IP?
(1) Ask DNS
(2) DNS reply IP
(3) compare network number
    --> ADD(IP, subnet mask)
(4) Ask default gateway for help