The main difference between US and international patents is that US patents provide protection within the United States, while international patents provide protection in multiple countries.
Utility patent application: may be filed by anyone who invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof.
Applicants who are lawful permanent residents of the United States may apply for registration. All other applicants who are aliens residing in the United States may apply for limited recognition to practice before the Office in patent matters pursuant to 37 CFR § 11.9(b).
Provisional patent applications with non-English specifications can be filed with the USPTO. In order for a nonprovisional application to claim priority to a non-English provisional, an English translation of the provisional needs to be timely filed along with a statement that the translation is accurate.
Who can apply for a patent? A patent application can be filed either by true and first inventor or his assignee, either alone or jointly with any other person. However, legal representative of any deceased person can also make an application for patent.
Although the WO designation itself does not confer patent rights, it simplifies the process by offering a common standard across the 184 PCT member countries, including the U.S., China, and European nations​.
Submit the application to the World Intellectual Property Organization (WIPO) or a national patent office. Your invention is then provisionally protected in all contracting states of the Patent Cooperation Treaty (PCT). The WIPO carries out a search on the state of the art (also known as the prior art).
You may apply for a U.S. patent whether you're a U.S. citizen or not. No U.S. patent can be issued if, before you apply in the United States, the invention was patented abroad by you or your legal representative and if the foreign application was filed more than 12 months before the U.S. filing.
A WO patent is granted by the World Intellectual Property Organization, or WIPO. The prefix WO, which is short for WIPO, indicates that the patent will be administered by this body. In general, the protection conferred on an invention by patent law will only extend to the country or territory in which it is patented.