I will describe various aspects of inflation in supergravity and string
theory. In many models of string theory, high energy scale inflation may
destabilize vacuum state and make the universe 10 dimensional. There is
a very special class of theories where high energy scale inflation does
not destabilize vacuum. In the context of such theories, we constructed
a broad class of supergravity-based inflationary models, which can
describe any possible set of the inflationary parameters n_s and r, as
well as small non-gaussianity of the spectrum of cosmological
perturbations. This is important because it allows to describe a large
variety of observational data in the context of models based on
supergravity.