If a car key has been made after 1998, it is probably a transponder key and contains a computer chip in it. The head of a transponder key is typically larger than that of a regular key.
Transponder keys or chip keys power a vehicle's ignition using circuits that emit signals with radio frequencies. They were created in the 1990s to prevent car theft, which happened at a high rate at that time. Each chip key is modified for each model to create a unique response and protect the vehicle. An auto dealership specific to the car model or an automotive locksmith has the expertise to determine if a key has a transponder.