What makes the wheels of a car move?

Answer 1

Lets keep it simple. Imagine you are sitting on a bicycle, your legs are the same as the pistons in an engine, they go up and down to deliver power to the crankshaft. That's the bit that goes through the large cog between your ankles with the chain around it. The chain transfers that power to the gears on the rear wheel. Here is the gear-box, depending on what gear you select with your gearlever that gear will transfer the power to the main drive cog fixed to the rear wheel.

If you have managed to get your head around that you will now appreciate that every time you have you toes on those pedals and your legs keep pumping, your back wheel will turn because the power of your legs has been transfered to the point where your tyre meets the roads surface. That transfer from driving force [engine/legs] to the tyre happens much the same for car or bycycle.