ESO Workshop, ESO Headquarters, Garching, Germany, 23–27 February 2015
Stellar halos are ubiquitous in luminous galaxies, but their low surface brightness hampers detailed study in distant galaxies. With the advent of large cameras and surveys, several late- and early-type galaxies have revealed similar low luminosity extended structures. These halos have complex morphologies with multiple stellar components, kinematics and substructures indicating the merger history. The halo morphologies resemble the density maps from cosmological simulations of galaxy formation in a hierarchical Universe.