At the end of The Rise of Skywalker, the First and Final Orders are destroyed, and 3 planets are shown witnessing the destruction of Imperial Destroyers.
The 2nd planet is the forest moon of Endor, home of the Ewoks, shown in Star Wars VI.
The 3rd planet is the desert world of Jakku, Rey's homeplanet, shown in Star Wars VII.
I cannot recognize the 1st planet though.
What are these planets? Endor, Jakku, and which else? When were they relevant in the Star Wars franchise?
It's Bespin (more specifically Cloud City), which is included because it played a major role in Star Wars Episode V: The Empire Strikes Back
This is the home of Lando Calrissian who had a major role in Episodes 5, 6 and (I assume ) 9 (because I haven't bothered seeing that one yet).
It is also the city where Luke dueled Vader for the first time in the movies, the place where he lost his hand, the place he learned that Vader is his father and the place where Han Solo got frozen in Carbonite.
