Phagocytes are the cells that protect the body by ingesting (phagocytosing) harmful foreign particles, bacteria, and dead or dying cells.
The term that describes the process through the cells of immune system engulf the microorganisms is called phagocytosis.
The cells that recognize and start the process of phagocytosis are macrophages and neutrophils. The macrophages and neutrophils engulf the pathogens and form the phagosomes. The phagosomes are then unified with lysosomes to create the phagolysosomes. The microorganisms are destroyed within phagolysosomes.
The molecule that makes the process of phagocytosis more efficient is called opsonin. The opsonin binds to the surface of microorganism like a label, helping the antibodies (IgG) to identify the molecules and fastening the process of phagocytosis.