  We investigate theoretical properties of beams of light with non-uniform
polarization patterns. Specifically, we determine all possible configurations
of cylindrically polarized modes (CPMs) of the electro-magnetic field,
calculate their total angular momentum and highlight the subtleties of their
structure. Furthermore, a hybrid spatio-polarization description for such modes
is introduced and developed. In particular, two independent Poincar\'e spheres
have been introduced to represent simultaneously the polarization and spatial
degree of freedom of CPMs. Possible mode-to-mode transformations accomplishable
with the help of conventional polarization and spatial phase retarders are
shown within this representation. Moreover, the importance of these CPMs in the
quantum optics domain due to their classical features is highlighted.
