Mobile WiMAX (WiMAX comes from "Worldwide Interoperability for Microwave Access") is a technical wireless standard allowing web browsing and wireless data transfer on the move. It's an another way of calling the 802.16e protocol.
WiMAX technology provides the equivalent of broadband speeds without the need for cables, and service coverage can extend over an entire city, region or even a whole country.
Access to the WiMAX wireless service is subject to a monthly subscription and it requires the use of a dedicated WiMAX modem, which is usually supplied for free by the operator.
WiMAX technology allows for data transfer speeds of up to 75Mbps, but in reality they tend to be a lot lower than that, at around 1-10 Mbps tops.