A patent is a grant of certain property rights for a limited time to an inventor of a novel invention, issued by the United States Patent and Trademark Office (USPTO). The owner of the patent may exclude others from importing, "making, using, offering for sale, or selling" the patented invention. However, a patent by itself does not necessarily confer the inverse rights onto the rights holder. Said another way, just because a rights holder has the patent for a particular invention does not mean that the rights holder may import, make, use, sell or offer to sell the subject of the patent. For example, other rights holders may own "blocking patents," or the patented invention may be regulated under other laws.

There are three main categories of U.S. patents utility, design and plant patents.

1. Utility patents are granted to those who invent or discover new and useful processes, machines, articles of manufacture, or compositions of matter. This also includes any new and useful improvement on existing processes, machines, articles of manufacture, or compositions of matter.
2. Design patents are granted to those who invent new, original, and ornamental designs for articles of manufacture; and
3. Plant patents are granted to those who invent or discover (and asexually reproduce) any distinct and new variety of plant.

Although only an inventor, patent agent or an attorney admitted to the patent bar may draft patent claims, or prosecute a patent application, attorneys who concentrate their practice in IP and litigation matters, but are not members of the patent bar, may litigate a patent infringement case all the way through appeal. These attorneys may also negotiate and draft sale, transfer or license agreements for nearly any subset of the patent rights. Many IP attorneys either only prosecute patent applications, or engage in patent litigation. Patent agents are only admitted to practice before the USPTO, and therefore generally may not repesent clients in court or, negotiate and draft a contract on their behalf. A focused IP attorney may not only represent you in court and negotiations, but can also give an opinion regarding other protections afforded certain forms of intellectual property such as copyrights, moral rights, digital rights management, trademarks and trade secrets.