This paper examines quasi-static magnetic processes such as those found in magnetic recording. We shall discuss the hysteresis in medium-hard magnetic materials of the type used in recording media, and the magnetizability of soft magnetic materials such as those used in recording heads. There are two general modeling techniques used to described these processes: physical modeling and phenomenological modeling. In physical modeling, the basic processes involved are simulated in order to be able to describe the basic magnetizing modes. On the other hand, in phenomenological models, the gross behavior of the material is described mathematically by Preisach-type models in order to couple the material properties to Maxwell's equations so as to obtain solutions of field problems. The latter models are computationally more efficient than the former, but they do not give any insight into the physical principles involved. © 1990 IEEE