Here's why:
* Dominance in its orbit: Neptune is the dominant gravitational body in its orbital region. It has cleared its neighborhood of other objects, which is a key criteria for being a planet.
* Round shape: Neptune is massive enough for its own gravity to have pulled it into a nearly round shape.
Dwarf planets, on the other hand, share some similarities with planets but also have key differences:
* Not dominant in their orbit: They haven't cleared their orbital neighborhood of other objects.
* Not always round: They may be irregularly shaped.
Therefore, Neptune meets the criteria for a planet, while dwarf planets do not.
