Radiation refers to the energy emitted in the form of waves or particles from a source. This energy can be in the form of electromagnetic radiation, such as light or radio waves, or it can be in the form of particles, such as alpha or beta particles. Research in the field of radiation typically focuses on understanding how radiation interacts with matter, how it can be used in medical imaging and therapy, and how it can be harnessed for nuclear energy production. Additionally, researchers in this field also study the potential health risks associated with exposure to radiation and ways to mitigate these risks.