The complement pathway is a part of the immune system that helps the body fight infections. It consists of a series of proteins that work together to identify and eliminate pathogens, such as bacteria and viruses. When activated, these proteins can directly destroy pathogens or mark them for destruction by other immune cells. There are three main pathways of the complement system: the classical pathway, the lectin pathway, and the alternative pathway. Each pathway is triggered by different signals but ultimately leads to a similar outcome—enhancing the immune response and promoting inflammation to help clear infections.