ELI5: Explain Like I'm 5

car engines

Car engines are like really big toys that power cars. They take the fuel that you put in your car and combine it with air to make a type of energy called power. Power is what makes the wheels turn and moves your car. Inside the engine, there are lots of different parts that work together to make power. These parts move up and down quickly to mix the fuel and air together and ignite it like a sparkler. This igniting (or spark) of the fuel causes a tiny explosion that pushes a piston down. As the piston moves down, it turns a special part called the crankshaft. The crankshaft turns a gear that turns the wheels of your car and moves it forward.