This document provides information about spectroscopy. It defines spectroscopy as the study of interaction of electromagnetic radiation with matter. It discusses the basic principles of UV-visible spectroscopy and infrared spectroscopy. UV-visible spectroscopy involves absorption of radiation in the visible and UV region, causing electrons to move between energy levels. Infrared spectroscopy analyzes absorption in the infrared region to determine molecular structure based on vibrational and rotational transitions. The document also defines key terms used in spectroscopy like chromophore, auxochrome, and discusses different types of shifts that can occur in absorption spectra.