||Mutualists may be symbiotic or nonsymbiotic.
- Symbiotic: two organisms living together in close association; individuals interact physically and their relationship is such that one cannot live without the other (i.e. fungal-algal symbiosis in lichens)
- Nonsymbiotic: Mutualists live independent lives yet cannot survive without each other (this type of mutualism is much more common). The example which most prevalent are flowers and pollinators.