  Swift opened up a new era in the study of gamma-ray burst sources (GRB).
Among a variety of discoveries made possible by Swift, here we focus on
GRB090423, the event at z=8.2 which currently holds the record of the most
distant celestial object ever caught by human instrumentation. This GRB allowed
us to have a direct look at the early Universe. The central engine activity
giving origin to the GRB emission is also discussed starting from the
observational findings of an updated GRB X-ray flares catalog.
