Radiation therapy is a type of cancer treatment that uses high-energy particles or waves, such as x-rays, gamma rays, electron beams, or protons, to destroy or damage cancer cells. It works by targeting the DNA within cancer cells, which prevents them from growing and dividing. This therapy can be used alone or in combination with other treatments like surgery or chemotherapy. The goal of radiation therapy is to kill as many cancer cells as possible while minimizing harm to healthy tissue.