Patents are often granted to inventors in order to protect their property rights. Te United States Patent and Trademark Office is responsible for granting patents in the United States, and issues patents for three categories: utility, design, and plant patents. US Patents may be applied for online using the US Patent and Trademark Office's electronic filing system located on their official website. Before submitting a patent application, conducting an online patent search is recommended in order to ensure that a patent has not already been issued for a specific creation. A patent search may be conducted using the online patents database. Patent attorneys or other businesses who assist in the patent application process are often consulted in order to help applicants with the process. Once an inventor is granted an official US patent, the inventor has the right to stop others from making, using, or selling their unique invention in the United States.