String theory and quantum gravity.

In this talk I review recent developments in superstring theory. In the first half of the talk I discuss some of the earlier developments in this subject. This includes a review of the status of string theory as a unified theory of gravity and other interactions, the role of duality in string theory, and application of string theory to the problem of information loss near a black hole. In the second half of the talk I review the developments of the last two years. This includes application of duality symmetries, Matrix theory, Maldacena conjecture, and derivation of gauge theory results from string theory. In choosing the list of topics for this talk, I have focussed on those which are likely to be of some interest to non-string theorists, thereby leaving out many of the marvelous technical results in this subject.