:Thank you for bringing that to my attention. The definition there was basically correct, but the relationship with other terms shaky. There are dominant bodies in solar orbit, the (major) planets, and populations of other bodies, the minor planets and comets, or per the 2006 IAU terms, dwarf planets and small Solar System bodies. All known comets are small Solar System bodies and the large majority of minor planets are also small Solar System bodies, but some of them are dwarf planets (with most of them not known for sure: list of possible dwarf planets). A planemo is any body that is round: the planets, dwarf planets, and the round moons (the Moon, the Galilean moons, and several moons of Saturn and Uranus, Triton, and Charon (there are also a few trans-Neptunian moons that could be round). Some people use "planet" with the meaning of "planemo", and then "major planet" is used to refer to the dominant eight that are called planets under the 2006 IAU definition. If there is still something you don't understand, don't hesitate to ask.