The term intellectual property (IP) is deprecated by some scholars in the field. The term patent denotes clarity and openness such as appears in the often-used phrase "patently obvious". The term IP is generally considered to encompass four major areas: patents, copyrights, trademarks, and trade secrets. The contract is between the public, represented by the US Government Patent and Trademark Office (PTO), and a natural person, the inventor. Patents are covered in this chapter, patent processes and copyrights are addressed later. The unqualified term patent is generally taken to mean a utility patent, which is emphasized in this chapter as being of most interest to engineers. The statutory basis for design patents appears in Title 35 section 171 through section 173. The determinations of what constitutes "prior art" and infringement in design patent cases are much more subjective than they are in most utility patent cases.