High-power lasers have opened new fields of application, the most prominent of which are probably controlled thermonuclear fusion and X-ray lasers. Because of its systematic, thorough, and self-contained presentation this book is a suitable introduction for the novice. Since it provides at the same time a comprehensive review of the progress made in the last 25 years, it may serve as well as a shelf reference for the specialist. The emphasis is on the physics of the processes observed in high-power laser-matter interaction and its exact theoretical description. Keywords are: laser generated plasma, plasma dynamics, nonlinear waves, wave-particle interaction, transport phenomena, nonlinear dynamics, radiation.