Why is my fan motor not turning on my 2005 Buick Ranier?

My 2005 Buick Ranier engine became overheated today while idling in park. I realized the fan for the motor was spinning at all. Any ideas of my identifying the problem myself?Why is my fan motor not turning on my 2005 Buick Ranier?The belt-driven fan or the electric fan? If the belt driven one wasn't turning then the clutch mechanism inside it is broken. If the electric one isn't turning then it could be a fuse or the switch that is suppose to turn it on when the engine is heated up.