Wide Area Network. As opposed to a LAN, a WAN is a network that can have extremely large geographic distances between devices. These distances are generally larger than an immediate metropolitan area and can be arbitrarily large.
Wired Equivalent Privacy. In 802.11 wireless networking, WEP defines the security standards used in making connections between an end device and an Access point.
See WAN.
An older packet-switching network technology. X.25 was similar in many ways to modern Frame Relay except that it operated at slower speeds and included more error-correction functions. X.25 VC's also tended to be switched (SVC) rather than permanent (PVC), as in Frame Relay.
Xerox Network System. XNS was an early suite of networking protocols that influenced the development of many later protocols, including both IP and IPX.