In current years we have used WPA and WPA 2 for the encryption of data sent over an 802.11 network. But in the past WEP is used . From time to time, many people say that WEP (Wired Equivalent Privacy) is a rather poor way of protecting data sent over an 802.11 wireless network. Is there any reason behind? What is the advantage of using WPA for the encryption of data sent over an 802.11 network ?
WEP has a flaw that renders it essentially unsecure. If you look at How does WEP wireless security work? it explains in better detail.
WPA(2) has fixed that vulnerability but they also suffer from their own problems.