  I review some of the basic observational details of jets from X-ray binaries,
or `microquasars'. It is shown that in both (Z and Atoll) NS and BHC systems
radio emission, and therefore jet formation, is correlated with the presence of
hard (30-500 keV) X-ray emission. At gamma-ray (> 500 keV) energies, the
relation is not so clear. Possible physical connections between the presence of
a jet, with a population of relativistic electrons, and the emission of hard
X-rays, are briefly discussed.
