An association between two organisms in which both benefit is called

An association between two organisms in which both benefit is called "symbiosis". Symbiosis is a close and long-term biological interaction between two different species, where both species benefit from the relationship. Examples of symbiosis include lichens, which are a combination of algae and fungi, where the algae produce food for the fungi, and the fungi provide a protective environment for the algae. Another example is the relationship between nitrogen-fixing bacteria and legumes, where the bacteria provide nitrogen to the plants, and the plants provide a source of energy and nutrients for the bacteria. Symbiotic relationships can be mutualistic, where both organisms benefit, or they can be commensalistic, where one organism benefits and the other is neither harmed nor helped.