  The optical and gamma-ray observations of GRB 080319B allow us to determine a
fairly complete physical picture for this remarkable burst. The data indicate
that the prompt optical and gamma-ray photons were produced at the same
location but by different radiation processes: synchrotron and synchrotron
self-Compton, respectively. The burst emission was produced at a distance of
10^{16.5} cm from the center of explosion by an ultra-relativistic source
moving at Lorentz factor of ~500. A straightforward inference is that about 10
times more energy must have been radiated at tens of GeV than that released at
~1 MeV. Assuming that the GRB outflow was baryonic and that the gamma-ray
source was shock-heated plasma, the collimation-corrected kinetic energy of the
jet powering GRB 080319B was larger than 10^{52.3} erg. The decay of the early
afterglow optical emission (up to 1 ks) is too fast to be attributed to the
reverse shock crossing the GRB ejecta but is consistent with the expectations
for the "large-angle emission" released during the burst. The pure power-law
decay of the optical afterglow flux from 1 ks to 10 day is most naturally
identified with the (synchrotron) emission from the shock propagating into a
wind-like medium. However, the X-ray afterglow requires a departure from the
standard blast-wave model.
