Directions in string theory

Strings are important objects for physics, although it has not been proved yet. It is a common hope, that they are fundamental elements of grand unification. Much less common is the hope that they describe color-electric fluxes and help to solve gluodynamics and also that they are relevant for the solution of the three-dimensional Ising model.In my talk I shall describe various topics, important for all three problems. I believe that in order to reach understanding it is useful to keep them in mind simultaneously.Unfortunately, my presentation will be fragmentary, because my understanding of the subject is far from complete.