This set of specification, also called the 902.11 family make-up the set of technologies we call Wi-Fi. Wireless networking devices communicate with each other through radio waves.
Different 802.11 standards generally use the same basic protocol, but might operate at different frequency bands. In NA, FM radio transmission operate between 88 and 108 megahertz. (FM broadcast band)
Wi-Fi networks operate on a few different frequency bands, most commonly the 2.4 GHz and 5.0 GHz bands.
There are lots of 802.11 specifications: (in adopted order)
802.11 = defining how we operate at both the physical and the data link layers
An 802.11 frame has a number of fields. The first is called the frame control field.
This field is 16 bits long and contains a number of subfield that are used to describe how the frame itself should be processed. This includes things like what version of the 802.11 was used.
It specifies how long the total frame is, so the receiver knows how long it should expect to have to listen to this transmission
Why are there four instead of the normal two?