For many years now, the standard way of starting a car was via an Ignition Key.
The key would normally have 3 positions
Position 1 would turn on Ancillary items and release the steering lock.
Positions 2 would turn on the ignition and the dashboard lights would illuminate and the car may carry out some self diagnostic checks.
As these were checked, lights on the dashboard would go out assuming no problems were found
Position 3 would make the engine start up. Once the engine had started you would release the key and it would return to position 2.
In Modern vehicles we now see different methods to start the car.
One of these methods is via a start button, and there would be no Ignition barrel.
The car would still have either a Key or a Key Fob, and these would send out a frequency that when in close proximity of the car would allow that activation of the Start/ Stop button.
There was no physical need to place a key into a slot, and they would usual remain in your pocket.
Once in the car, by pressing the Stop/Start button once, all the dashboard lights illuminate and self diagnostic checks are carried out by the car.
By then depressing the clutch pedal to the floor and pressing the Stop/start button once again the engine will start.
To save two presses of the Stop/Start button you could just enter the car depress the clutch pedal and press the Stop/Start button.
The engine would start up and the diagnostic checks will still be carried out.
In certain brands of car, this Key Card would replace the standard keys or key fob.
I suppose you could also call it a Card Fob.
The buttons on the Card allow you to lock or unlock the car and maybe just the boot on it's own.
Once you are in the car the Card usually has a slot somewhere on the dashboard where you would insert it. A frequency is emitted and allows you to start the car in the same manner as the Stop/Start method.
Always ensure when using a Faraday Pouch, that it is fully sealed/closed when in use. Just the slightest gap can allow the signal being emitted to be scanned by thieves.