WiMAX is an acronym that stands for Worldwide Interoperability for Microwave Access, a certification mark for products that pass conformity and interoperability tests for the IEEE 802.16 standards.
WiMAX is a standards-based wireless technology that provides high-throughput broadband connections over long distances. WiMAX can be used for a number of applications, including "last mile" broadband connections, hotspots and cellular backhaul, and high-speed enterprise connectivity for business.
Products that pass the conformity tests for WiMAX are capable of forming wireless connections between them to permit the carrying of internet packet data. It is similar to WiFi in concept, but has certain improvements that are aimed at improving performance and should permit usage over much greater distances. A WIMAX wireless internetmap of coverage is being publicly developed now.
IEEE 802.16 is working group number 16 of IEEE 802, specializing in point-to-multipoint broadband wireless access.

The 802.16 family of standards has been dubbed “WiMAX” by an industry group called the The WiMAX Forum. The mission of the Forum is to promote and certify compatibility and interoperability of broadband wireless products. The acronym WiMAX expands to "Worldwide Interoperability for Microwave Access".