  Understanding the physics and geometry of accretion and ejection around super
massive black holes (SMBHs) is important to understand the evolution of active
galactic nuclei (AGN) and therefore of the large scale structures of the
Universe. We aim at providing a simple, coherent, and global view of the
sub-parsec accretion and ejection flow in AGN with varying Eddington ratio,
$\dot{m}$, and black hole mass, $M_{BH}$. We made use of theoretical insights,
results of numerical simulations, as well as UV and X-ray observations to
review the inner regions of AGN by including different accretion and ejection
modes, with special emphasis on the role of radiation in driving powerful
accretion disk winds from the inner regions around the central SMBH. We propose
five $\dot{m}$ regimes where the physics of the inner accretion and ejection
flow around SMBHs is expected to change, and that correspond observationally to
quiescent and inactive galaxies; low luminosity AGN (LLAGN); Seyferts and
mini-broad absorption line quasars (mini-BAL QSOs); narrow line Seyfert 1
galaxies (NLS1s) and broad absorption line quasars (BAL QSOs); and
super-Eddington sources. We include in this scenario radiation-driven disk
winds, which are strong in the high $\dot{m}$, large $M_{BH}$ regime, and
possibly present but likely weak in the moderate $\dot{m}$, small $M_{BH}$
regime. A great diversity of the accretion/ejection flows in AGN can be
explained to a good degree by varying just two fundamental properties: the
Eddington ratio $\dot{m}$ and the black hole mass $M_{BH}$, and by the
inclusion of accretion disk winds that can naturally be launched by the
radiation emitted from luminous accretion disks.
