Patents provide inventors with a government-authorized monopoly over their inventions for a limited time. There are three main types of patents: utility patents, which protect inventions or improvements to machines and processes; plant patents, which protect new varieties of plants; and design patents, which protect the visual appearance of manufactured objects. Obtaining a patent is important because it allows inventors to profit from their inventions and deters copying by competitors. Inventors can obtain a patent by hiring a patent attorney or filing a provisional patent application themselves, which establishes an early priority date and allows marking an invention as "patent pending" while a full non-provisional application is prepared.