Equus is a planet, and prime home for the Pony race, along with many other similar creatures unique to this world. It is also once sighted by the Gems of Homeworld, but for unknown reasons decide to abandon it, leaving many animals alone on the planet. While ruled by Ponies, there's many examples of other Sentient species that're known to exist such as Dragons, Griffons, and other mythical creatures.
The exact layout of Equus on a global scale is unknown at this time, but according to the maps, the world is made up of at least two to three continents: one being Equestria, and the other being currently unknown. The most well-known area of Equus is Equestria itself, which is assumed to be the prime continent of the planet.