Phagocytes refer to the procedure by which some kind of living cells known as phagocytes engulfs or ingest other cells or particles. The phagocyte may be a free-living one-celled species, like an amoeba, or one of the body cells, like a white blood cell.
In higher species, phagocytosis is mainly a defensive mechanism against infection and invasion of the body by the antigens, that is, foreign particles.
Thus, phagocytosis is illustrated by most types of white blood cells ingesting bacteria, viruses, and other foreign substances.