Abstract: Radiation therapy being most general treatment modality to cure patients with different malignancies covers more than fifty percent of cancer burden. Since its inception for treatment of cancer and other malignancies in 1896, development of new devices from time to time has brought several changes in techniques of radiation therapy. The present study aims to present an outlook towards the basic concepts involved related to radiation therapy and to highlight the development of the various techniques of radiation therapy involving wide range of energies from x-ray, γ-ray and charged particles.