A complement component refers to a part of the complement system, which is a crucial aspect of the immune system. This system consists of proteins that work together to help the body fight infections and clear damaged cells. When activated, complement components can enhance the ability of antibodies and phagocytic cells to eliminate pathogens. There are several complement components, often labeled with numbers, such as C1, C2, and C3. These components can be activated through different pathways, leading to a cascade of reactions that ultimately help in opsonization, inflammation, and cell lysis. This process is vital for maintaining the body's defense against various diseases.