Leptogenesis is a class of scenarios in which the cosmic baryon
asymmetry originates from an initial lepton asymmetry generated in the
decays of heavy sterile neutrinos in the early Universe. I explain why
leptogenesis is an appealing mechanism for baryogenesis, and I review
its motivations and the basic ingredients. I will then address in some
detail the connections between leptogenesis and the scale of the light
neutrino masses generated via the seesaw mechanism. I conclude by
discussing which future experimental results could provide
circumstantial evidences for leptogenesis.
