This book discuss new recent and exciting results in the field of accretion and ejection physics onto supermassive black holes at the center of active galactic nuclei (AGN). Through a uniform and systematic analysis of the X-ray spectra of a large sample of Seyfert and radio galaxies observed with the XMM-Newton and Suzaku satellites, here we report the statistical significance of blue-shifted Fe K absorption lines at energies higher than 6 keV. A curve of growth analysis and detailed modeling are reported as well. This allows to estimate the general parameters of the associated ultra-fast...