Discusses structure-property relationships in metallic alloys selected to illustrate some basic concepts of physical metallurgy and alloy design. Fundamentals of annealing, spinodal decomposition, nucleation, growth, and particle coarsening. Concentrates on structure, structure formation, and structure-properties relationships. Also considers structural features: grain size, interstitial and substitutional solutes, precipitates, second-phase particles, and eutectoids. Examples from advanced structural alloys and low-dimensional alloys for magnetic recording media and integrated circuits.