Phagocytosis is a process used by certain cells, known as phagocytes, to engulf and digest harmful particles, bacteria, or dead cells. During this process, the phagocyte surrounds the target with its cell membrane, forming a pocket that eventually pinches off to create a vesicle called a phagosome. This vesicle then merges with a lysosome, which contains enzymes that break down the engulfed material. This mechanism is crucial for the immune system, as it helps to eliminate pathogens and debris from the body. Macrophages and neutrophils are two types of phagocytes that play a significant role in defending the body against infections and maintaining tissue health.