  Gamma Ray Bursts (GRBs) show evidence of different light curves, duration,
afterglows, host galaxies and they explode within a wide redshift range.
However, their spectral energy distributions (SEDs) appear to be very similar
showing a curved shape. In 1993 Band et al. proposed a phenomenological
description of the integrated spectral shape for the GRB prompt emission, the
so called Band function. We present an alternative scenario to explain the
curved shape of GRB SEDs: the log-parabolic model.
