The document discusses the history and applications of Raman spectroscopy. It describes how Raman spectroscopy was discovered in 1928 by Sir C.V. Raman using sunlight and optical filters. Raman won the Nobel Prize in 1930 for this discovery. Raman spectroscopy provides information on a sample's chemical composition and molecular structure by analyzing the inelastic scattering of monochromatic light, usually from a laser. It is used to study vibrational, rotational, and other low-frequency modes in a system.