Astrography and Astropolitics
Human Space is about 400 parsecs across and is divided up into nine administrative zones, called (somewhat inaccurately) 'Quadrants'.
The eponymous Quadrant Zero is the central quadrant, wherein lies Earth - the home of humanity and all the oldest colonised worlds, the 'Home Worlds'.
Around Quadrant Zero are eight other quadrants, numbered 1 to 8. These
contain the colonial worlds - frontier worlds that are, on the whole,
much less developed that those of Quadrant Zero.
Communication and travel times between the outer quadrants and Quadrant
Zero are measured in months - so all polities with an interest in the
outer quadrants maintain separate arms of government in each quadrant
- headed by a Governor (or the equivalent).
In other cases, the political fallout from such a conflict can spill
over into Quadrant Zero.