  We review recent progress in our understanding of the nature of gamma ray
bursts (GRBs) and in particular, of the relationship between short GRBs and
long GRBs. The first example of a short GRB is described. The coincidental
occurrence of a GRB with a supernova (SN) is explained within the induced
gravitational collapse (IGC) paradigm, following the sequence: 1) an initial
binary system consists of a compact carbon-oxygen (CO) core star and a neutron
star (NS); 2) the CO core explodes as a SN, and part of the SN ejecta accretes
onto the NS which reaches its critical mass and collapses to a black hole (BH)
giving rise to a GRB; 3) a new NS is generated by the SN as a remnant. The
observational consequences of this scenario are outlined.
