Wide Area Network (WAN)
A Wide Area Network (WAN) provides communication and information sharing over a large geographical area.
WANs are collections of interconnected local area networks (LANs), which are limited to a physical location. Without WANs enterprises and users on a LAN would be limited to the information and user base in just location. WANs are developed by telecommunications service providers, who then lease these capabilities to multinational or otherwise large enterprises requiring this degree of connectivity.
The Internet is the largest known example of a WAN. Going further, NASA is developing Disruption Tolerant Networking (DTN) that stores data and relays it to correct delays, for use in interplanetary communications including for the International Space Station (ISS).
“The Internet is the largest public WAN, connecting countless LANs so that there is one information-sharing and communications platform for everyone — no matter how far dispersed they are — providing there is connectivity.”