Spectroscopy is often used in physical and analytical chemistry for the identification of substances through the spectrum emitted from or absorbed by them. Spectroscopy is also heavily used in astronomy and remote sensing most large telescope have spectrometer, which are used either to measure the chemical composition and physical properties of astronomical objects or to measure their velocity from the doppler shifts of their spectral lines. There are some types of spectroscopy we will discuss here i.e. UV Spectroscopy, IR Spectroscopy, HPLC Spectroscopy. The overview and study of that instruments are also important.