What is the name that is given to a symbiotic relationship in which both species benefit?

This kind of relationship is called mutualism and is defined by both parties being equally beneficial to each others survival. An example of this kind of relationship is found a lot in nature, as with the relationship between fish and coral reefs in the sea. Corals provide shelter and protection for the small fish while the fish in return also provide protection from algae and seaweed invading in on their space and killing off the coral.