Commensalism : In this interaction one species is benefitted and the other species is neither benefitted nor harmed.
e.g. an orchid growing as an epiphyte on the branch of a mango.
Mutualism : In this interaction both the interacting species are benefitted.
e.g. Lichens exhibit mutualistic relationship between a fungus that absorbs water and nutrients from soil and photosynthesizing algae / cyanobacteria.