Not all wireless standards are the same, and you should become familiar with the differences and similarities of each.
TA B L E Wireless standards
So why all the different letters in the 802.11 family? Well, the short answer is that the additional letters correspond to the working groups that came up with the modifications to 802.11. For example, 802.11a refers to the standard that defines changes to the physical network layer required to support the various frequency and modulation requirements.