Symbiosis (from Greek συμβίωσις, symbíōsis, "living together", from σύν, sýn, "together", and βίωσις, bíōsis, "living")[2] is any type of a close and long-term biological interaction between two biological organisms of different species, termed symbionts, be it mutualistic, commensalistic, or parasitic.[3] In 1879, Heinrich Anton de Bary defined it as "the living together of unlike organisms". The term is sometimes used in the more restricted sense of a mutually beneficial interaction in which both symbionts contribute to each other's support.