This is an introduction to the science that is beginning to emerge on state-of-the-art synchrotron radiation facilities which should flourish with the forthcoming x-ray free-electron lasers. The book is intended for the use by scientists at synchrotron radiation facilities working with the combination of x-rays and lasers and those preparing for the science at x-ray free-electron lasers. During the 1990s synchrotron radiation sources have experienced a tremendous increase in their brilliance and other figures of merit. This progress, driven strongly by the scientific applications may actually be accelerating with the advent of x-ray free-electron lasers. As a result, a confluence of x-ray and laser physics is taking place, due to the increasing importance of laser concepts, such as coherence and nonlinear optics to the x-ray community and the importance of x-ray optics to the laser-generation of ultrashort pulses of x-rays.