  In this set of lectures I review recent developments in string theory
emphasizing their non-perturbative aspects and their recently discovered
duality symmetries. The goal of the lectures is to make the recent exciting
developments in string theory accessible to those with no previous background
in string theory who wish to join the research effort in this area. Topics
covered include a brief review of string theory, its compactifications,
solitons and D-branes, black hole entropy and web of string dualities.
(Lectures presented at ICTP summer school, June 1996)
