<P>This book provides a comprehensive introduction to ultrafast phenomena, covering the fundamentals of ultrafast spin and charge dynamics, key methods, and applications in physics, chemistry, and materials science. The authors explain in clear language how an ultrafast laser pulse can induce rapid responses in electrons and spins in solids and nanostructured materials. They also show how this field is driving the next generation of magnetic storage devices and ultrafast intense light sources, incorporating numerous examples and problems throughout.</P>