Endor itself is not the moon, but instead the planet which the moon orbits (or orbited). The planet Endor is never visible in the film, a fact which the novelisation explains by asserting that it was destroyed some time earlier and that the moon now orbits its star in a planetary orbit of its own.
Some fans of the movie with some knowledge of physics have noted that if the destruction of the second Death Star actually occurred as depicted, the moon would have been rendered uninhabitable. This is known as the Endorian Holocaust. There is still a great deal of speculation on this point.
The Star Wars planet is named after J.R.R. Tolkien's Endor, probably an allusion to the similarity between Ewoks and Hobbits, or the moon's tall foliage and the mellyrn of Lothlórien.
Endor'smoon is also the location of the two Ewok TV movies Caravan of Courage: An EwokAdventure and Ewoks: The Battle for Endor, as well as the adventures of the animated series StarWars: Ewoks.
The Endor Holocaust is the theorized devastation of the forest moon of Endor which happened after the second Death Star was destroyed (in StarWars Episode VI: Return of the Jedi) by the impact of falling debris.
Endor - Wookieepedia, the StarWars Wiki - A Wikia wiki
The planetEndor was never visible in any scenes in Return of the Jedi set on the forest moon, a fact which the novelization explains by asserting that it was destroyed some time earlier, and that the moon now orbits its star in a planetary orbit of its own.
StarWars Battlefront 2 shows the planetEndor as a large blue planet, possibly a gas giant, when in Galactic Conquest mode.