  We report studies of the electronic structure and elementary excitations of
doped and undoped cuprate chains, ladders and planes. Using high energy
spectroscopies such as x-ray absorption, core level photoemission and angle
resolved photoemission spectroscopy, important information regarding the charge
distribution and hole dynamics can be obtained. The comparison of the
experimental data with suitable theoretical models sets constraints on the
parameters entering into the model calculations, and offers insight into the
important physical quantities governing the electronic structure of these
materials. Recurring themes include the importance of the dimensionality of the
Cu-O network (1D->2D) and the crucial role played by the spin-background in
determining the dynamics of low-lying excitations in these strongly correlated
systems.
