X-ray scattering is used extensively to provide detailed structural information about materials. Semiconductors have benefited from X-ray scattering techniques as an essential feedback method for crystal growth, including compositional and thickness determination of thin layers. The methods have been developed to reveal very detailed structural information concerning material quality, interface structure, relaxation, defects, surface damage, etc.This book provides a thorough description of the techniques involved in obtaining that information, including X-ray diffractometers and their associated instrument functions, data collection methods, and the simulation of the diffraction patterns observed. Also presented are examples and procedures for interpreting the data to build a picture of the sample, much of which will be common to materials other than semiconductors.