A U.S. territory is a partially self-governing piece of land under the authority of the U.S. government. U.S. territories are not states, but they do have representation in Congress. There are five U.S. territories: American Samoa, Guam, the Northern Mariana Islands, Puerto Rico, and the U.S. Virgin Islands. Each territory is allowed to send a delegate to the House of Representatives.
The people who live in American Samoa are considered U.S. nationals; the people in the other four territories are U.S. citizens. Citizens of the territories can vote in primary elections for president, but they cannot vote in the general elections for president.