  We review some of the ways that X-ray observations provide unique information
on radio galaxies. Thermal bremsstrahlung X-ray emission provides detailed data
on ambient densities and temperatures. These parameters in turn can be used for
pressure balance calculations and can demonstrate how the ambient gas affects
radio source structure. Additionally, many signatures of the interaction of
radio jets and lobes with the hot gas are found in high resolution X-ray maps.
  Non-thermal X-ray emission from knots and hotspots of radio jets can give us
constraints on the relativistic electron population for energies greater that
that normally sampled in the radio (in the case of synchrotron emission) or can
give us an independent estimate of the average magnetic field strength (if
inverse Compton emission is the origin of the X-rays). From recent ROSAT HRI
observations of 3C 390.3 and 3C 120, we show evidence that X-ray emission from
knots and hotspots appears to be associated with regions of large gradients in
the radio surface brightness; i.e. at the location of powerful shocks.
