Typically, every modern car has power door locks installed within their automobile. These locks can be controlled in multiple ways. The most common way is with the wireless remote control. This mechanism allows the user to safely lock and unlock their car without using the actual key. The way this works is that the user would press either the lock or unlock button on the device and the device would then emit a frequency unique to the car in question. That frequency is then picked up by the computer within the car, which then activates the actuators controlling the locks, ultimately locking or unlocking the vehicle.
Another way of contolling these locks is through the proximity key. This technique is less common, however, requires even less work than pressing a button. This key activates the locks when the user enters the "bubble" of the car, or the area in which the signal can be picked up by the computer. Once the user is in the "bubble" the computer activates the actuators unlocking the car, similar, yet different to the example above.