WiMAX stands for Worldwide Interoperability for Microwave Access. It is a telecommunications technology providing wireless data over long distances in a variety of ways, from point-to-point links to full mobile cellular type access. It is based on the WirelessMAN (IEEE 802.16) standard.
WiMAX is a highly scalable, long-range system, covering many kilometers using licensed spectrum to deliver a point-to-point connection to the Internet from an ISP to an end user. WiMAX can be used to provide a wireless alternative to cable and DSL for broadband access, and to provide high-speed data and telecommunications services. WiMAX can also be used to Connect many Wi-Fi hotspots with each other and also to other parts of the Internet.
When using WiMAX device with directional antennas, speeds of 10 Mbit/s at 10 km distance is possible, while for WiMAX devices with omni-directional antennas only 10 Mbit/s over 2 km is possible. There is no uniform global licensed spectrum for WiMAX, although three licensed spectrum profiles are being used generally – 2.3 GHz, 2.5 GHz and 3.5 GHz [wiki]
With WiMAX enabled handsets and laptops coming into the market, people could connect to the fast broadband internet from anywhere, without having to depend on the slow rate mobile network data transfer. You can work on broadband, call friends and colleagues and watch real-time TV from the top of a forest hill station many kilometers away from the access point – without compromising on quality, speed or screen size!
WiMAX could connect remote Indian villages to the Internet using broadband. This would avoid hassles in cabling through the forests and other difficult terrain only to reach a few people in remote places. Maintaining such system would also be easy. WiMAX could provide Internet access, voice and IPTV to those areas.
Comparison with Wi-Fi
Simply put, if WiMAX provides services analogous to a cellphone, Wi-Fi is more analogous to a cordless phone.
Wi-Fi is a shorter range system, typically hundreds of meters, typically used by an end user to access their own network. Wi-Fi is low cost and is generally used to provide Internet access within a single room or building. For example, many coffee shops, hotels, railway stations and bus stations contain Wi-Fi access points providing access to the Internet for customers.
Wireless Routers which incorporate a DSL-modem or a cable-modem and a Wi-Fi access point, often set up in homes to provide Internet-access and inter-networking to all devices connected (wirelessly or by cable) to them. One can also connect Wi-Fi devices in ad-hoc mode for client-to-client connections without a router. Wi-Fi allows LANs to be deployed without cabling for client devices, typically reducing the costs of network deployment and expansion. Wireless network adapters are also built into most modern laptops. [wiki]
For example, I have a BSNL DataOne broadband Wireles DSL modem at home. I can freely work from my Wi-Fi enabled laptop anywhere in my home or even from its premises.