A wide range of atomic and solid state phenomena is studied today by means of x-ray excitation or inner-shell ionization, as this volume strikingly illustrates. The strong link between these two fields of investigation is partly the result of the extensive developments within each and also largely due to the broad variety of theoretical and experimental techniques now available. All im- portant recent advances are to be found highlighted here; most are substantially reviewed. Two dominant research threads are evident in, the chapters of this book. While clearly distinguishable, they are...