  I review the current status of our theoretical understanding of Pulsar Winds
and associated nebulae (PWNe). In recent years, axisymmetric models of pulsar
winds with a latitude dependent energy flux have proved very successful at
explaining the morphology of PWNe as seen in the X-rays. This success has
prompted developments aimed at using multi-wavelength observations of these
nebulae as a diagnostics of the hidden physics of the pulsar wind and of the
mechanism(s) through which particles are accelerated in these sources. I will
discuss these most recent developments in terms of the information that we
infer from detailed comparison of simulated non-thermal emission with current
observations.
