Anti-cancer agents are substances that help prevent, slow down, or stop the growth of cancer cells. These agents can be found in various forms, including medications, natural compounds, and even certain foods. They work by targeting specific processes in cancer cells, such as their ability to divide and spread. Common types of anti-cancer agents include chemotherapy drugs, which kill rapidly dividing cells, and immunotherapy, which boosts the body's immune response against tumors. Additionally, some herbal remedies and nutrients are being studied for their potential protective effects against cancer.