A Wired Equivalent Privacy (WEP) is a deprecated wireless security protocol that was designed to provide a wireless local area network (WLAN) with a high level of security and privacy similar to the security and privacy of a wired LAN. Unfortunately, it has been shown to be very insecure by security researchers. In fact, so many security problems were discovered with WEP that it is not recommended to be used and no patches were created to fix the wholes. Instead new wireless protocols like WPA and WPA2 were released to provide the necessary WiFi security users demanded.
Do Not Use WEP anywhere ever again.
Source: TechTarget
Related Terms: VLAN, Virtual Private Network (VPN)