  Coherent effects manifested in light scattering from cold, optically dense
and disordered atomic systems are reviewed from a primarily theoretical point
of view. Development of the basic theoretical tools is then elaborated through
several physical atomic physics based processes which have been at least partly
explored experimentally. These include illustrations drawn from the coherent
backscattering effect, random lasing in atomic gases, quantum memories and
light-atoms interface assisted by the light trapping mechanism. Current
understanding and challenges associated with the transition to high atomic
densities and cooperativity in the scattering process is also discussed in some
detail.
