Drafting is a term frequently used for cars, but it also can be used in other racing vehicles. If one car is following another car too closely, nearly bumper to bumper, then one might say that the car is drafting the other car. Drafting essentially is a racing technique. When cars move they create a pocket of high-density air, and a pocket of low-density air. This creates drag, which can slow the vehicle down. When drafting, a car following another car enters into and shares this bubble of air formed by the lead car. This allows both cars to gain a little more speed since both cars are sharing the same pocket of air. It's aerodynamics. But the rear driver has the advantage because of the slingshot effect, which is when the rear car moves to pass, the low pressure from the first car will suck the rear car forward. As the rear car is sucked forward, the shape of the low-density bubble surrounding the lead car will change. As the bubble's shape changes the front car is slowed down, as the air readjusts the pocket of low-density air. So what does this mean? This means the car that was once behind has used the pocket of air made by the other car to slingshot itself infront of the other car. The lead car can be passed relatively easy using this method. This means that even a slower car can draft on a faster car, share its pocket of air, then slingshot out and pass the faster car.