An interaction between two populations of animals in which one (the predator) hunts, captures, and kills the other (the prey) for food. Predator-prey relationships form important links in many food chains. They are also important in regulating population sizes of both predator and prey, especially when the predator relies on a single prey species. The term predation is also used, more loosely, for any feeding relationship in which an organism feeds on any other living organism (animal or plant).