What are the different pieces of a patent?

Patents have a fairly standard format. The top of the patent includes the name of the inventor, the entity to whom patent rights might be assigned (often an inventor assigns a patent to his employer if the invention was conceived as part of his work for that employer), the patent number, the date the patent application was filed, the date the patent issued, the classes and subclasses under which the patent was classified (for whatever classification system is used; normally the U.S. or European classification systems), and the classes the examiner searched when determining if the invention was novel.

The real substance of a patent consists of an abstract (a very brief summary of the invention), the claims (which legally determine exactly what the patent covers and what it does not), and a description. The description may contain several parts, including a section titled "FIELD OF THE INVENTION" (which puts the invention in context by briefly describing the field of technology or business to which the patent is applicable), the "BACKGROUND OF THE INVENTION" (which describes previous, similar inventions, and the problems which remained unresolved, setting the stage for why this invention is new and useful), the "SUMMARY OF THE INVENTION" (which then describes the current invention), the "BRIEF DESCRIPTION OF THE DRAWINGS" (which relates to drawings that are part of the patent), and the "DETAILED DESCRIPTION" (which can be extremely detailed, and talks about exactly how the invention works, refers to every diagram, and often attempts to broaden the scope of the patent by suggesting other ways that the invention could be used or implemented other than just what is presented in the figures).

Finally, near the top of the patent you will also see references to other patents, and sometimes some references that are not other patents (we refer to this as "non-patent literature"). These are the references that either were provided by the inventor (often as a result of a patent search), or found by the patent examiner. Ostensibly, they constitute the prior art closest to the current invention. (Hint - they can provide good leads for a patent search.)