  We present our current understanding of the formation and early evolution of
protostars, protoplanetary disks, and the driving of outflows as dictated by
the interplay of magnetic fields and partially ionized gas in molecular cloud
cores. In recent years, the field has witnessed enormous development through
sub-millimeter observations which in turn have constrained models of protostar
formation. As a result of these observations % that the observations provided,
the state-of-the-art theoretical understanding of the formation and evolution
of young stellar objects is described. In particular, we emphasize the
importance of the coupling, decoupling, and re-coupling between weakly ionized
gas and the magnetic field on appropriate scales. This highlights the complex
and intimate relationship between gravitational collapse and magnetic fields in
young protostars.
