If you are going to some hotel, there will be someone that will attend to you if you have a car. They will park it to whatever number you would want them to park it on as long as it is available. They are called valet and their job is to park your car.
In this game, you are the valet and you would want to impress the boss by doing your job right. Client will appear one at a time and will ask you to park their cars. Remember the number you park it on as you will have to retrieve it later. Try not to damage it as you will be fired.