This title reviews in-depth research on accretion on all scales, from galactic binaries to intermediate mass and supermassive black holes. Possible future directions of accretion are also discussed. The following main themes are covered: a historical perspective; physical models of accretion onto black holes of all masses; black hole fundamental parameters; and accretion, jets and outflows. An overview and outlook on the topic is also presented.

Foreword.- Searching for Black Holes in Space.- General Overview of Black Hole Accretion Theory.- Fast Variability from Black-Hole Binaries.- Modelling Spectral and Timing Properties of Accreting Black Holes: The Hybrid Hot Flow Paradigm.- Current Status of Simulations.- Observational Tests of the Picture of Disk Accretion.- Observational Appearance of Black Holes in X-Ray Binaries and AGN.- Scaling Relations from Stellar to Supermassive Black Holes.- Menus for Feeding Black Holes.- Massive Binary Black Holes in Galactic Nuclei and Their Path to Coalescence.- Mass Measurements of Stellar and Intermediate-Mass Black Holes.- Measuring the Masses of Supermassive Black Holes.- Measuring Black Hole Spin Using X-Ray Reflection Spectroscopy.- Black Hole Spin via Continuum Fitting and the Role of Spin in Powering Transient Jets.- An Overview of Jets and Outflows in Stellar Mass Black Holes.- X-Ray Observations of Powerful AGN Outflows.- Outflow Launching Mechanisms.- Energetic and Broad Band Spectral Distribution of Emission from Astronomical Jets.- Jet-Environment Interactions as Diagnostic of Jet Physics.-The Supermassive Black Hole Galaxy Connection.- Multi-Wavelength Variability.- Black Hole Studies: Overview and Outlook.