Commensalism is a type of interspecific interaction in which one species is benefitted and the other species is neither harmed nor benefitted.
Example of commensalism:
The interaction between egrets (birds) and grazing cattle is an example of commensalism. Cattle egrets are birds that live near the cattle. The birds catch the insects found near the cattle, which are otherwise hard to catch. In this interaction, only egrets are benefitted. While grazing, the cattle stir up and flush out insects from the vegetation which the bird feeds on.