This is to be initial, 'overview' volume of a series on the "Chemistry of Advanced Materials". This series of volumes is intented to complement VCH's existing series on "Materials Science and Technology" and, in particular, to highlight the role of chemistry in the preparation and processing of advanced materials. The introductory volume in the series is intented to "set the stage" for the succeeding volumes and to introduce the subject of materials chemistry to a general audience of scientifically literate nonspecialists. Subjects covered in this intitial volume will eventually be the subject of one or more individual volumes in the series. This series is directed to a broad audience of chemists and materials scientists. This volume, in particular, should be appropriate for a general scientific audience and be of interest, as well as comprehensible, even to undergraduate students in chemistry and materials science.