The free spectrums that Wi-Fi uses for its transmissions
The various variants of the 802.11 standard that collectively make up Wi-Fi
Other (non-Wi-Fi) wireless standards and how they relate to Wi-Fi
You don't have to understand a whole lot about Wi-Fi to be able to make good use of it. Therefore, this chapter does not go into a great deal of technical detail about the various Wi-Fi standards. You'll find some of the gory, geeky details in Appendix A, "Wireless Standards," if you really need to know.
Still, there are a number of good reasons for you to have some basic understanding of how wireless technologies work and the alphabet soup of standards they use. A little information will help you make knowledgeable decisions when you buy equipment. It is interesting to know enough about the technical things to see which way this fast-moving technology is going. And, knowing something about this stuff (even if it is only how to pronounce "gigahertz") is a good way to impress your friends, neighbors, and co-workers.
This chapter tells you everything you really need to know about the wireless standards related to Wi-Fi.