Synchrotron light is an ideal tool for many types of research in materials science, physics, and chemistry and is used by researchers from academic, industrial, and government laboratories. Several methods take advantage of the high intensity, tunable wavelength, collimation, and polarization of synchrotron radiation at beamlines which are designed for specific kinds of experiments. The high intensity and penetrating power of synchrotron X-rays enables experiments to be performed inside sample cells designed for specific environments. Samples may be heated, cooled, or exposed to gas, liquid, or high pressure environments. Experiments which use these environments are called in situ and allow the characterization of atomic- to nano-scale phenomena which are inaccessible to most other characterization tools. In operando measurements are designed to mimic the real working conditions of a material as closely as possible.