Generally a patent is a reward granted to an inventor in exchange for teaching others about the invention. It is a limited right which generally provides a right to exclude others from making, using, selling or importing something which infringes upon the rights of the inventor. It is sometimes referred to as a letters patent and is distinguishable from a land patent which refers to land or real property. Historically, a patent was issued by a monarch or government granting exclusive rights to a person granting them exclusive rights throughout the kingdom. In addition, historically printing patents were also issued, which was a precursor to today's modern copyright registration system.
In the U.S., the term patent usually refers to the right granted to an inventor who invents a new, useful, and non-obvious process, machine, article of manufacture, or composition of matter. Some other types of intellectual property are industrial design rights which are called design patents in the US and plant breeders' rights called Plant Patents in the U.S.
As a subcategory of utility patents, some people refer to biological patents, business method patents, chemical composition patents and software patents. These are all just subcategories of utility patents in reference to their particular technology but legally they are still utility patents.