A patent is right symbolized by a document granted to the owner of a creative work to exclude others from making, using or selling the work described in the document. The patent is issued by the federal government by application. The patent has an expiration period of 20 years. Following expiration, the invention becomes public domain and everyone is free to exploit it. The purpose of granting patents is to encourage public disclosure of technical advances and provide the creator monopoly over his work.

The rules and regulations promulgated by the U.S. United States Patent and Trademark Office are extensive and complicated. The first important requirement that an inventor should comply with is timeliness. An application for patent must be filed within a year following certain acts, such as the public disclosure of the work or the sale and use of the work. Other countries in the world do not grant this one-year grace period so American inventors who seek to obtain foreign patents must file an application for patent first in the United States before publicly disclosing the work. In the United States, patents are granted to the person who first created the work. To prove this, the inventor must keep complete record of the progress of his work, from the day the idea was hatched. Prior to the application of the patent, the inventor must do extensive research to check whether someone else has already been granted a patent to the same or similar invention. The invention and the method by which it will be used must be thoroughly described in the application. The description is in writing or in drawing.

Not all inventions are granted patents. The proper subject matter of a patent is any product or process, including genetically modified bacteria or plants. There are numerous requirements laid out by federal law, and the non-compliance on one would mean the denial of the entire application. Federal law requires the invention to be new, which means it has not yet been invented by another or used in another county before the actual invention date. The invention must also be useful or has commercial worth. In addition, the invention must also pass the non-obviousness test, which means that a person with ordinary would not have found the invention obvious at the time it was made. These are requirements that must be determined prior to the application of patent. The determination of patentability must be conducted by an expert patent law attorney to save the cost and time of applying for a patent only to be rejected later on because the patentability test is not met.

The primary purpose for the application of patents is to take commercial advantage of the invention in order to recoup the high cost of research and development. Like any other type of property, rights granted in a patent can be sold or rented. An inventor can earn directly by practicing his invention or indirectly by selling the patent. Inventors must take note though that they cannot practice their invention freely if its practice would encroach on the patent of another inventor. This means that if the invention needs another part and that part is not licensed or is licensed to another person, the inventor cannot practice the invention as he might be subjected to an infringement case. The two inventors, however, can agree to work together and freely use each other's invention. By selling patent or granting exclusive licenses to his patent. Patents are very valuable and, if used in the best possible way, will pave for a technologically advanced society.