What is the PTO?
The Patent and Trademark Office, often referred to simply as the PTO, is the United States Patent and Trademark Office, an office of the U.S. Department of Commerce. The PTO is responsible for granting and overseeing patents and trademarks. Thus, when a patent or trademark application is being filed, it is filed with the PTO, and if a patent or trademark registration is ultimately granted, it is granted by the PTO.
With regard to trademarks, there are PTO employees known as examining attorneys, or simply examiners. These examiners review submitted trademark applications to determine whether the trademark can be federally registered. For more information, you can go to the PTO’s surprisingly useful website.