  After recalling a few basic concepts from cosmology and string theory, I will
outline the main ideas/assumptions underlying (our own group's approach to)
string cosmology and show how these lead to the definition of a two-parameter
family of ``minimal" models. I will then briefly explain how to compute, in
terms of those parameters, the spectrum of scalar, tensor and electromagnetic
perturbations, and mention their most relevant physical consequences. More
details on the latter part of this talk can be found in Maurizio Gasperini's
contribution to these proceedings.
