What is the smallest unit of territory?

[Me_]

What is the smallest unit of territory that can be owned and what is the smallest unit of territory that can be transferred between players?

In CK2 the smallest thing one can own is a barony, but baronies usually go together with counties. In Victoria 2 one can own a province, but in peace deals you can only transfer whole regions.

What is the smallest unit of territory in Stellaris? Is it a system? Can two players have planets in one system? Can a planet be divided between two players? Is there competition for colonization? Can a planet be partially mine and partially in the hands of a minor player?

Just how messy can the borders get?

 

[drakeheath]

I think planets have cities, or something like continents, places you can build stuff on planets and have populations.

 

[Thure]

I think I read somewhere that planatas can have multiple regions.

 

[Georilla]

I think I read somewhere that planatas can have multiple regions.

That would be likely, considering the discussion of multiple factions/POP's living on a planet.