| Mutualism | It is beneficial interaction. Both species are benefitted and is given as + and +. Example is mycorrhizae and higher plants. |
| Commensalism | This is an interaction where one species is benefitted (+) and other is neutral. Example is epiphytes growing on tree branches. |
| Amensalism | This is an interaction where one species is harmed (-) and other is neutral. Example is fungus like Penicillium and bacteria. |
| Parasitism | This is a negative interaction. One species (the parasite) is benefitted and the host is harmed. |