Quasicrystals have been the object of intense research efforts for a good 16 years now. In recent years, this area of solid state physics and crystallogra­ phy has grown into a mature field in its own right. Hence, several books on quasicrystals have appeared in the interim (see Appendix) and chapters on quasicrystals have been introduced into new books on solid state physics and l into new editions of existing monographs. However, most of the former have been written for scientists specialised in this field rather than for students, and the latter additions are often rat her brief. We therefore decided to fill the gap between these two extremes with a book which provides an introduction to the structure and physical properties oi quasicrystals and covers, in sufficient detail, all important fields in qua­ sicrystal research and even applications. The chapters have been written by specialists and each is based on the author's insight into this field. Howe­ ver, much effort has been put into achieving an introductory character and making the text accessible to newcomers to the field.