In the death throes of a massive star's demise, the stellar core collapses to an ultra-dense state, generally a neutron star for all but the most massive progenitors. Born spinning rapidly, with immense magnetic fields, many such neutron stars act as pulsars, with cosmic generators producing teravolt potentials that result in winds of relativistic particles. The extended nebulae formed as pulsar winds expand into their surroundings provide information about the composition of the winds, the injection history from the host pulsar, and the supernova ejecta into which the nebulae are expanding. Recent modeling coupled with important observations from nearly all parts of the electromagnetic spectrum has placed important constraints on a significant number of individual systems and their host remnants, and on the population as a whole.
Here I provide a broad overview of the structure and evolution of pulsar wind nebulae, with specific examples of observations extending from the radio band to very high energy gamma-rays, and of hydrodynamical studies of these nebulae evolving within their host supernova remnants.
