This book addresses the issue of translating a number of microscopic relaxation mechanisms into a language adapted to the peculiarities of the dynamics of the magnetization vector. It brings to light some previously unexplored, and some unexpected, features of that dynamics. Only modest mathematical equipment is
employed throughout, but some familiarity with the simpler properties of ferromagnets at the level of advanced undergraduates or first year graduate students is assumed. The book should also be of some interest to professionals in the magnetic recording industry.