A key is a tool that is used to open and close the locks built in objects that are to be protected from outside access. When the first locks were invented, they were large metal boxes that need keys to open very large and heavy iron. However, in the twentieth century has been a big evolution in the design of new systems for closing the doors which led to a very wide range of keys. Most keys are made of steel, but in cars or other premises and using keys to incorporate a system for open distance without entering the key into the lock, only if it is introduced because of lack of batteries or damage ceases to operate the electronic opening distance. These keys also serve to start up the engine of the car.