This is the first book which reviews the most important results obtained in the past decade for layered copper-oxide high-temperature superconductors by neutron scattering techniques. The following topics are thoroughly introduced, methodically discussed and highlighted with the most important results by acknowledged experts in their respective fields: static and dynamical properties of the crystal lattice (oxygen site occupation, charge transfer, charge-stripe order, phonon dispersions and density-of-states), static and dynamical magnetic correlations (phase diagrams, 2D and 3D magnetic ordering, spin waves and spin fluctuations, crystal-field excitations) and the structure of the flux-line lattice (field and temperature dependence). The 2D features of the copper-oxide perovskites are found to be essential for achieving high-temperature superconductivity by doping. The book addresses an interdisciplinary audience, both specialists and those entering the field. Emphasis is put on the fundamental properties; however, technological applications are evidently emerging from these basics.