What are the basic difference between Wimax , WiFi and Gsm system???

What is a Wimax network?
What is a WiFi network?
What is a GSM or CDMA network?
First i have to know what are those different type of networks what are the basic definition and difference between them.
I basically understand that in cell phone network mainly GSM and CDMA is used and some Mobile operators supports WiFi technology. But i have no clear idea of how it is done and what are the differences. All those network are wireless and works on signals or frequencies. But not all device supports all type of frequencies that's why mobile and modem are required.
This is my experience but I don't know how does it work. So I will be glad if someone can explain it with some examples and definitions that I will be easy to understand.
Best of luck. See you.
