Parasitism

Symbiosis
When two different species work together for their mutual benefit, the relationship is known as a symbiotic association, and the involved species are known as symbionts. Examples of symbiotic relationships include phycobiont and mycobiont affiliations in lichen, rhizobium associations in root nodules, and mycorrhizal relationships in various species. Ectosymbiosis, like the mycorrhizal connection, is when two species live apart from one another. Endosymbiosis, on the other hand, is when one organism lives inside the other, like algal cells within the fungal matrix in lichens and rhizobium bacteria in plant root nodules.