They were developed in the late 90s due to technological advancement. When placed in the ignition, they communicate with the ignition receiver. One advantage of transponder keys is that they add a security layer to the ignition, acting as anti-theft devices. Once they detect a wrong signal, they alert the car owner. Information can be found here.
Switchblade car keys
They operate like switchblades. The shank is hidden in a folded manner when car keys are not in use. Switchblades can be purchased separately. As such, it easier to replace them if the car keys are damaged. See here for information about How to Get Car Key Replacement.
Laser-cut car keys
Laser-cut car keys can be differentiated from normal keys by their thickness. They are thicker than basic car keys with fewer carved groves.
Smart keys.
Smart keys fobs that can stay in the pocket and can be used to ignite a car by pressing a button on the car’s dashboard. The technology is one of the safest because it randomly rolls the car's security code to curb theft.
Traditional keys and fob
It is the key that comes designed by the car dealer. It has no additional security feature except its special cut. It looks exactly like the normal apartment keys.