WAN stands for Wide Area Network. It is also similar to a LANs and WANs network but in addition to that, WAN is not restricted to a single or geographical location. Rather, it may be restricted within the bounds of a state or maybe a country.
Many WAN network extends its area or distance by using satellite links and the technology is high speed and comparatively expensive. The Internet is a perfect example of a public WAN and could be described as the biggest WAN in the world today.