Duality in N=1 Supersymmetric gauge theories and recent developments

We discuss a number of exact results in N=1 supersymmetric field theories. We review the results obtained by Seiberg in Super-Yang-Mills (SYM) theories with matter in fundamental representation. We then consider Kutasov-type SYM theories, which also contain matter in the adjoint representation and an appropriate tree--level superpotential. We finally focus on one particular case in the latter theories, a generalization of the theories with equal number of flavors and colors studied by Seiberg, in which non--trivial superconformal theories appear at certain sections of the quantum--modified moduli space. Throughout the paper we stress the role played by duality in the search for exact results.