Book excerpt: A discussion by an assembly of expert physicists and materials scientists, embracing the specific features of vortex-pin interactions, the modes of different kinds of vortex motion under the action of Lorenz force, and the mechanisms of dissipation. The effects of transport and screening currents, superimposed AC magnetic fields and the microwave electromagnetic irradiation on vortex behaviour define the electromagnetic properties of a high-Tc superconducting material. The mechanisms driving the depinning of vortices and the dynamics of their motion determine the critical current density and its file dependence, the mechanisms of energy dissipation, and linear and nonlinear resistivity, AC losses, and noise in electronic circuitry. The book therefore has direct implications for the development of new devices and components in electrical engineering, modern electronics, computer technology, and microwave communication.