Slipstream
A slipstream is the pocket of low-pressure air behind a car, which lets a following driver reach a higher top speed on a straight.
Also called tow
Also called a tow. The car in front pushes the air aside, and the one behind meets less resistance — worth several km/h down a long straight, and the basis of most overtakes at circuits like Monza.
It is why qualifying at those tracks becomes a game of positioning: a driver wants a tow on the straights without being close enough through the corners to lose downforce in dirty air.