Fan Controllers Help?!?!

Can someone explain how you set up a fan controller in a PC and how the fans connect etc. what connections do you have and stuff like that, cheers.

Fan controllers are used to control the speed of fans individually.  Some use touchscreen, LED, or physical switches. Most are powered through a molex connector, and most controllers use 3 pin connectors although some use 4 pins.  when picking out a fan connector make sure to calculate the correct wattage for your fans.

cheers for the help