How do histocompatibility antigens help the immune system in recognizing and distinguishing between self and non-self cells?

Histocompatibility antigens, also known as human leukocyte antigens (HLAs), help the immune system recognize and distinguish between self and non-self cells by serving as markers on the surface of cells. These antigens play a crucial role in immune responses by allowing the immune system to identify and target foreign invaders while avoiding attacking the body's own cells.