Jump leads, also known as jumper cables, are electrical cables used to connect a dead battery to a charged one, allowing the dead battery to receive a boost of power. They typically have two insulated cables, one red for positive connections and one black for negative connections. This method is commonly used to start vehicles with drained batteries, such as cars or trucks. To use jump leads, you first connect the red cable to the positive terminal of the dead battery and then to the charged battery. Next, the black cable is connected to the negative terminal of the charged battery and then to a metal ground on the vehicle with the dead battery. This process helps transfer electrical energy, enabling the vehicle to start.