The Communion is the collective name for all the intelligent species capable of communicating with one another. The peoples of the Communion are able to interact socially, economically and intellectually despite their cultural and psychological differences. Communion species may war with one another because they have similar and conflicting interests.
The boundaries of the Communion are subjective and ill-defined: to humanity a species might be so alien that it is not considered “Communion”, but to some Others that same species might be more comprehensible.
Beings that are generally agreed to be beyond the Communion are called Strangers.