What is a network?
OSI & TCP/IP models
Local area network (LAN)
Wide area network
Encapsulation
Ethernet
Ethernet frame
MAC addresses
IP addresses
Unicast addresses
Multicast addresses
Broadcast addresses
Network devices
Network hubs
Network bridge
The term wide area network is used to describe a network that spans multiple geographic locations. Consider an example. A company has two offices, one in London and one in Berlin. Both offices have a LAN. If the company connects these two LANs together using WAN technology, a WAN is created.
The key difference between LANs and WANs is that the company usually doesn’t own WAN infrastructure. A company usually leases WAN services from a service provider. A WAN spanning multiple cities could look something like this:
Frame Relay, ATM and X.25 are different types of WAN technologies. The Internet can also be considered a WAN.