WiMAX is another name for IEEE 802.16, an international standard that allows for computers to be networked together and access the internet wirelessly. Although similar to Wi-Fi, WiMAX has a much broader range, and allows for faster data transfer speeds.
Because of the fact that a single WiMAX base station can cover an entire metropolitan area, it allows for true mobility rather than having to hop from hotspot to hotspot as is necessary with Wi-Fi connections.