WiFi is a universal wireless networking technology that utilizes radio frequencies to transfer data. WiFi allows high-speed Internet connections without the use of cables.
The term WiFi is a contraction of "wireless fidelity" and commonly used to refer to wireless networking technology. The WiFi Alliance claims rights in its uses as a certification mark for equipment certified to 802.11x standards.
WiFi is a freedom – freedom from wires. It allows you to connect to the Internet from just about anywhere — a coffee shop, a hotel room, or a conference room at work. What’s more – it is almost 10 times faster than a regular dial-up connection. WiFi networks operate in the unlicensed 2.4 radio bands, with an 11 Mbps (802.11b) or 54 Mbps (802.11a) data rate, respectively.
To access WiFi, you need WiFi enabled devices (laptops or PDAs). These devices can send and receive data wirelessly in any location equipped with WiFi access.
Now, the focus in wireless is shifting to wide area, i.e., WiMax. WiMax, short for Worldwide Interoperability for Microwave Access, is defined in IEEE 802.16 standards. It is designed to deliver a metro area broadband wireless access (BWA) service, and is being promoted by the WiMax Forum.
WiMAX is quite similar to WiFi, but on a much larger scale and at faster speeds. A nomadic version would keep WiMAX-enabled devices connected over a large area, much like today's cell phones.
For more detail on WiMAX, you can go through our WiMAX Tutorial.