We review the phenomenon of coherent bremsstrahlung (CB) of electrons in a crystal. This well-studied process in a new light after the realization by Andersen [J. U. Andersen,Nucl. Inst. and Methods170, 1 (1980)] that CB and the phenomenon of channeling radiation (CR) are two aspects of the same physical process. These two types of radiation may be described in a unified framework by the use of Bloch functions for the electron in the crystal. The kinematics of CB is discussed from this viewpoint and a model calculation for CB in a strained-layer superlattice is presented.