In international relations, polarity is any of the various ways in which power is distributed within the international system. International relations scholars distinguish among unipolar, bipolar and multipolar scenarios depending on whether there is at the global level one, two, or more than two centers of power, respectively, though the term "multipolar" is also sometimes used to refer to scenarios that are not unipolar, i.e. where there is more than one center of power (Bostrom 2014: ch. 11).
Bostrom, Nick (2014) Superintelligence: Paths, Dangers, Strategies, Oxford: Oxford University Press.