Whereas LAN technologies tend to focus on connecting a large number of systems that are in close proximity to each other to a very fast network, WAN technologies tend to focus on interconnecting LANs and making connections to remote sites and resources. There are three main categories of WAN networks:
Internet— The Internet is, obviously, the largest WAN on the planet. With roots in the ARPAnet (Advanced Research Projects Agency Network), the Internet is used to provide a global network of resources and access points known as Internet service providers (ISPs). More and more companies are using the Internet as a connection medium, securing the traffic in VPN tunnels.
Intranet— An intranet is a private network based in concept ...