DRS stands for Drag Reduction System, and it is a driver-controlled device aimed at aiding overtaking and increasing the chances of wheel-to-wheel racing in Formula 1. The system involves the driver opening a flap in their rear wing to reduce drag levels and gain top speed when running within a second of a car in front. The flap is an integral part of the wing creating downforce, but it can be moved to an "open" horizontal position when the driver pushes a button on the steering wheel, reducing drag and increasing top speed. DRS can increase the car speed between 10 and 30 kilometers an hour, increasing the chance of overtaking a slower car. DRS usage is only allowed when the driver is within one second of the car ahead, and it can be used at any time during practice and qualifying, but only within the set activation zones. The effectiveness of DRS depends on the level of downforce at a given circuit, the length of the activation zone, and the characteristics of the track immediately after the DRS zone.