Belts are a meta classification that refer to a collection of Small Body objects in a stable orbit around a star or planet.
Circumstellar belts are individual bodies in orbit around a star. The difference between a belt and a disc tends to be that a belt is viewed as a collection of individual objects, whereas a disc is viewed as a much wider band of smaller particles which aren't considered individually.
- Asteroid Belt - A belt of rocky small bodies, with a mixture of rock, ice and metals.
- Dust Disc - A disc of dust and very small planetesimals. Generally only found in young star systems that are still in the planet forming stage.
- Ice Belt - A belt of mostly icy small bodies beyond the snow line.
- Metallic Belt - A belt of mostly metallic small bodies, very rare.
- Oort Cloud - A cometary cloud at the fringes of a solar system.
- Planetesimal Disc - A disc of objects somewhere between a Dust Disc and an Asteroid Belt.
- Vulcanian Belt - A belt of rocky small bodies with a high metal content close to their star.
A Belt can have moons. In this case these are major worlds (normally large asteroids) within the belt. Internally, the moon's distance is measured from the middle of the belt, so may be negative if it is on the inner half of the belt. 'Moons' that are part of a belt are called planetoids.