Originally a biological term in which two partners derive
mutual benefit from close association. The smaller of the two parties was called the
symbiont and the other was the
host.
The term as used in biology now means a close relationship of two or more organisms from different species in which at least one of the partners derives benefit.
There are three main types of symbiotic relationships:
Mutualism - where both or all parties benefit from the interaction.
Parasitism - where one party benefits at the expense of another.
Commensalism - where one party benefits and the other is unaffected.
The term has now gained
widespread use outside of biology and can be found applied to almost any close
interaction between any
combination of people, corporations, branches of science,
technologies, ideas, and anything else you can possibly think of.