Capital (Earth-2042)

The capital of a planet or territory is usually the primary city and is the seat of that planet or territory's government. However, a capital will not always be the largest city of that area. Similarly, a capital world is the primary planet in a star system and to an extension, the whole sector. Often a capital planet of a sector is simply the oldest (and most known or advanced) inhabited planet. It is common custom in the galaxy to name sectors and systems after their capital planet. For example Corellia > Corellia system > Corellia sector.

Source

 * https://starwars.fandom.com/wiki/Capital/Legends