1X EVDO stands for EVolution Data Optimized, a wireless broadband data standard used in many CDMA providers around the world. QualComm had the initial design in 1999 to meet IMT-2000 (International Mobile Telecommunications-2000) standards being better than 2Mbit/s downlink for stationary communications.
Verizon currently implements 1X EVDO called V Cast for high speed data speeds for mobile phones. Verizon and Sprint both provide this service in most major U.S. cities. EVDO is based the 1xRTT standard technology that provides two to three times internet speed of dial-up. Since it is based on 1xRTT, if an user goes outside of the EVDO coverage zone, the user automatically is transferred to 1xRTT standard making internet access very convenient.
The advantages Evdo has over WiFi is that it has seamless roaming, customers can access corporate VPN anywhere they can get a signal, realtime downloads, and signal travel on cell phone cell sites.