Macrophages are a type of white blood cell that play a crucial role in the immune system. They are responsible for identifying, engulfing, and digesting cellular debris, pathogens, and foreign substances. Macrophages can be found in various tissues throughout the body and are essential for maintaining overall health by helping to prevent infections and facilitating tissue repair. These cells originate from monocytes, which are another type of white blood cell. When monocytes leave the bloodstream and enter tissues, they differentiate into macrophages. Macrophages also help activate other immune cells, making them vital for coordinating the body's response to infections and inflammation.