The term ceramic comes from the Greek word keramikos, which means burnt substance. The desirable properties of these materials are normally achieved through a high-temperature heat treatment called firing. Up until the past sixty years, the most important materials in this class were called traditional ceramics, for which the raw material is clay, e.g. china, bricks, tiles and in addition, glasses and high-temperature ceramics. Recently, significant progress has been made in understanding the fundamental character of these materials and of the phenomena that occur in them that are responsible for their unique properties. Consequently, a new generation of these materials has evolved, and the term ceramic has taken on a much broader meaning. These new materials are applied in, e.g. electronics, computers, communication technology, biomedical implants and aerospace.