A patent family is all of the patents and patent applications resulting from a specific patent application. A patent is a set of exclusive rights granted by a government to an inventor or applicant for a limited amount of time (normally maximum 20 years from the filing date, depending on extension). ... A patent application is a request filed before a patent office in which an applicant applies for a patent for an invention. ... A patent application is a request filed before a patent office in which an applicant applies for a patent for an invention. ...

Generally, a patent application for an invention is filed in one country. Sometimes that original patent application is the basis for filing patent applications in several other countries. Each of these new patent applications can become the basis for filing subsequent patent applications. A single patent occasionally results in many, many patents througout the world.

When one patent application results in several patents in many different countries, all of the patents and applications associated with the original patent application is called the patent family.