Compton scattering is a phenomenon that occurs when a photon, such as an X-ray or gamma ray, collides with a charged particle, typically an electron. During this interaction, the photon transfers some of its energy to the electron, causing the electron to recoil and the photon to change direction and lose energy. This results in an increase in the wavelength of the scattered photon, a shift known as the Compton wavelength shift. This effect was first observed by physicist Arthur H. Compton in 1923, providing evidence for the particle-like behavior of light. Compton scattering is significant in various fields, including astrophysics, where it helps explain the behavior of high-energy photons in cosmic environments, and in medical imaging, where it influences the design of imaging techniques.