= Dwarf planet
A <dwarf planet>, in the International Astronomical Union's 2006 Solar-system definition, is a body that orbits the <Sun>, has enough <self-gravity> to assume a nearly round <hydrostatic equilibrium> shape, has not cleared its orbital neighborhood, and is not a <natural satellite>. The classification combines a body's physical shape with its dynamical environment; it is not defined by size alone.<Definition of a Planet in the Solar System by the International Astronomical Union>[Adopted planet-definition resolution, category 2 and its four criteria]{ref}
<Pluto> illustrates why both aspects matter: it is rounded but belongs to the trans-Neptunian population rather than being dynamically dominant in its orbital region. <Ceres> provides another example, in the <asteroid belt>. A rounded <Moon> does not become a <dwarf planet>, because the satellite exclusion is explicit. Under this terminology, planet and <dwarf planet> are distinct categories.<Definition of a Planet in the Solar System by the International Astronomical Union>[Adopted categories and accompanying classification of Pluto and Ceres]{ref}
Clearing does not mean that literally no other object shares the region. It concerns orbital dominance over the surrounding population. Nor does the rounding requirement supply one universal diameter threshold: resistance to deformation depends on composition, internal structure and rotation. Observations of shape and mass therefore address one part of the definition, while orbital-population information addresses another. The cited resolution is explicitly about the <Solar system>; applying the same wording to an <exoplanet> population requires an additional convention.
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