  This article gives an overview of gamma-ray bursts (GRBs) and their relation
to astroparticle physics and cosmology. GRBs are the most powerful explosions
in the universe that occur roughly once per day and are characterized by
flashes of gamma-rays typically lasting from a fraction of a second to
thousands of seconds. Even after more than four decades since their discovery
they still remain not fully understood. Two types of GRBs are observed:
spectrally harder short duration bursts and softer long duration bursts. The
long GRBs originate from the collapse of massive stars whereas the preferred
model for the short GRBs is coalescence of compact objects such as two neutron
stars or a neutron star and a black hole. There were suggestions that GRBs can
produce ultra-high energy cosmic rays and neutrinos. Also a certain sub-type of
GRBs may serve as a new standard candle that can help constrain and measure the
cosmological parameters to much higher redshift than what was possible so far.
I will review the recent experimental observations.
