A patent is an exclusive set of rights, granted by the government, to an inventor or somebody assigned by the inventor. Patent rights are only goof for a limited period. Patents last for 20 years and are a useful method of protecting inventions and designs for inventions that you have created. Two kinds of patents exist and they are design and utility. An example of a utility would be a patent for a bicycle. An example of a design would be a patent for a certain style or type of bicycle. It is best to think of design patents as patents for an alteration to an existing application. Since there are many different types of bikes, there are many different patents. There are mountain bikes, road bikes and hybrid bikes to name a few. To protect these alterations, patents must be filed. The patents are then monitored and protected by the United States Department of Commerce, Patent and Trademark Office.