The interaction between sea anemone that has stinging tentacles and the clownfish that lives among them is:
commensalism
Commensalism is an interaction where one organism benefits while the other is unaffected. This relationship between the sea anemone and the clownfish of a similar type, the clownfish benefits from living inside a sea anemone home because the stinging cells of the sea anemone provide it protection from many predators, while the sea anemone is unaffected by this relationship. Mutualism, on the other hand, is a mutually beneficial relationship. Amensalism harms one partner, while the other is unaffected. And competition is a relation that harms both the organisms involved.