Spintronics, being a part of electronics, is under intense development for about forty years and mainly concerns transport of electronics spin in low-dimensional structures. This field, based on often difficult theoretical concepts of quantum physics, has surprisingly strong and real technological and application consequences. Thus, spintronic solutions concern memory systems, information processing devices and are used as sensors to detect variety of physical fields. The early development of this field can be associated with the names of such scientists as: E. I. Rashba, A. Fert, P. Grünberg, J. Barnas, B. Hillebrands, G. Güntherodt, I. K. Schuller, M. Grimsditch, A. Hoffman, P. Vavassori, and S. Datta. This list is absolutely not closed and might be easily extended, however, it results rather from scientific history and contacts with people who influenced the research carriers of the authors. The authors give in this up-dated 2nd edition an insight into this emerging field providing theoretical and experimental aspects of spintronics and guide readers from a basic understanding of fundamental processes to recent applications and future possibilities opened by ongoing research. The textbook is suited for students and for interested scientists who were discouraged by the theoretical formalism only.