Grazing generally describes a type of predation in which a herbivore feeds on plants (such as grasses), and also on other multicellular autotrophs (such as algae). Grazing differs from true predation because the organism being eaten is not killed, and it differs from parasitism as the two organisms do not live together, nor is the grazer necessarily so limited in what it can eat (see generalist and specialist species). Grazing is important in agriculture, in which domestic livestock are used to convert grass and other forage into meat, milk and other products.