Any interaction between two species that benefits both; typically involves the exchange of substances or services.
An economic theory and anarchist school of thought that advocates a society where each person might possess a means of production, either individually or collectively, with trade representing equivalent amounts of labor in the free market.
A close, prolonged association between two or more organisms of different species that normally benefits both members. An interspecies cooperation.
The occurrence of two different or opposing things in the same time and place.
A close, prolonged association between two or more organisms of different species, regardless of benefit to the members.
The state of people of different types, races, cultures, communities, etc., living together.
A relationship of mutual benefit, especially among different species.