The term "chemotherapy" refers to the use of drugs or other substances to treat disease, particularly cancer. Chemotherapeutic agents are medications that are specifically designed and used for this purpose. They work by killing or stopping the growth of cancer cells in the body. These drugs can be administered in various ways, including orally (pills), intravenously (through a vein), or topically (applied directly to the affected area). Chemotherapy is often used in combination with other treatments such as surgery and radiation therapy to increase its effectiveness.