A planet, often called a world, was a celestial body that was in orbit around a star. Planets often had smaller bodies called moons that could be in orbit around the planet. Many planets were habitable, meaning it was suitable for sentient beings to live on. There were two known types of planets: terrestrial planets and gas giants. Although gas giants were generally uninhabitable, floating constructs such as Cloud City could be built wherein if the planet had a habitable layer. A group of planets, moons, and asteroids orbiting around a star were collectively called a star system. The galaxy was home to thousands of star systems. Although planets usually orbited only one sun, some, such as Tatooine, were located in binary star systems. Certain planets were strong with the Force, such as Dathomir.
"Homeworld" was a term used to describe the original home of a species, organization, or person. For example, Ryloth was the homeworld of the Twi'lek species, and the Human species were believed to have originated on the planet Coruscant.
It was possible to destroy a planet, although it would require a massive superweapon, such as a Death Star. It was also possible to turn a planet itself into a superweapon, as in the case of the First Order's Starkiller Base, which was capable of destroying entire star systems, such as the ill-fated Hosnian.