  Superstring theories at low energy limit are described by the corresponding
supergravities, and their non-perturbative D-brane/O-plane excitations are
described by DBI and WZ actions. Higher derivative corrections to these
effective actions are important for understanding the stringy behavior of the
fundamental objects. They may be extracted from the contact terms of the
corresponding S-matrix elements. On the other hand, the superstring theories
enjoy the T- and S-dualities which appear in the S-matrix elements as duality
Ward identities. These Ward identities might be used as generating functions
for constructing the S-matrix elements. The dualities may also be used directly
to construct the effective actions. In this article, we review the duality Ward
identities which can be used to generate S-matrix elements, and review the
dualities which may be used directly to construct the higher derivative
corrections to the effective actions.
