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Abstract: Comets, asteroids and moons that orbit stars and planets exterior to our solar system are prefixed with "exo". While the existence of these objects is certain, our understanding of their physical properties, composition, and diversity is still in its infancy, especially when compared to similar objects within our own solar system. This chapter introduces the topics of exocomets, exoasteroids, and exomoons, putting in context three emerging subfields in astronomy that, despite being relatively small, have experienced rapid growth over the past decade.