  The discoveries that GRBs have X-ray, optical and radio afterglows have
connected the study of GRBs to the rest of astronomy, and revolutionized the
field. In this review, I discuss the implications that the observation of these
afterglows have for burst energies and luminosities, and for models of the
bursts and their afterglows. I describe recent evidence linking the long,
softer, smoother GRBs detected by BeppoSAX and core collapse supernovae.
Finally, I summarize recent work showing that, if these GRBs are due to the
collapse of massive stars, they may provide a powerful probe of the very high
redshift universe.
