Phagocytosis is an important process of the immune system by which pathogens are internalized and eliminated by phagocytic cells. Upon internalization, the phagosome matures and acidifies while being transported in a centripetal fashion.
Phagosome maturation is the process by which internalized particles (such as bacteria and apoptotic cells) are trafficked into a series of increasingly acidified membrane-bound structures, leading to particle degradation.