XUV spectroscopy, also known as extreme ultraviolet spectroscopy, is a branch of spectroscopy that deals with the study of the interactions between matter and light in the extreme ultraviolet (XUV) range of the electromagnetic spectrum. This range typically extends from about 10 to 124 nanometers in wavelength. XUV spectroscopy is used to investigate the electronic structure and dynamics of atoms, molecules, and solids, as well as to study processes such as photoionization, Auger decay, and high-order harmonic generation. This research area is important for understanding fundamental physical and chemical properties of materials, as well as for applications in fields such as materials science, biochemistry, and nanotechnology.