What is the nature of WiFi signals?

There (their) properties and nature?

Wouldn't it be easier to ask someone to explain, in detail, how wi-fi works?

I'm sure an A2K boffin will happen this way and enlighten us.

(chances are, if you're not British, Irish, Australian or Kiwi, you'll have to look up the word boffin)

Even though this file is a bit old, it shows in detail the nature of the Wifi:

Wifi technology

Wifi technology simply works on fetching & reliving the data signals. Router you use for the wifi in your home or offices will get the data and relay it by doing some process on it.

A wireless network uses radio waves, communication across a wireless network is a lot like two-way radio communication.
1.A computer wireless adapter translates data into radio signals and transmits it using antenna
2.A wireless router receives the signal and decodes it. The router sends the information to the Internet.

It's all in the waves, man.

Essentially they are light. Just at the wave length our brains don't interpret into anything so we don't "see" them.