The term Wi-Fi (Wireless Fidelity) is often used in discussions of 802.11 networks. It refers to certification by the Wi-Fi Alliance, an international nonprofit association of 802.11 product vendors. 802.11 products that receive Wi-Fi Certification have been tested and found to be interoperable with other certified products. That means you can use your Wi-Fi certified product with 802.11 Wi-Fi Certified networks, whether they are Mac or Windows-based networks. Although 802.11 products that don't have Wi-Fi Certification may work fine with certified devices, the Wi-Fi Certified logo is your assurance of interoperability. AirPort Extreme is Wi-Fi Certified for 802.11b and 802.11g, which means that it works with any 802.11b or 802.11g Wi-Fi Certified products.
Apple is a member of the Wireless Ethernet Compatibility Alliance (WECA), which provides the Wi-Fi certification. You can find a list of certified Wi-Fi products at the Wi-Fi Alliance web site (
http://www.wi-fi.org/).