The 600–700 million-year-old complement system is an intelligent and well-organized defensive mechanism. It is widely regarded as a crucial component of innate immunity that strengthens the phagocytic cells' and antibodies' deadly effect when an organism defends itself against pathogens, apoptotic, and necrotic cells. But because the complement system can coordinate immune responses by interacting with various cells engaged in both the innate and adaptive immune responses, research conducted in the last few years suggests that the complement system may operate as a link between the two immune response branches. Additionally, antibodies produced by the adaptive immune system have the ability to recruit and activate the complement system. Moreover, the immune complement system aids in preserving the solubility of immune complexes in circulation and makes their removal easier.