  Within the AdS/CFT correspondence, we review the studies of field theories
with a large number of adjoint and fundamental fields, in the Veneziano limit.
We concentrate in set-ups where the fundamentals are introduced by a smeared
set of D-branes. We make emphasis on the general ideas and then in subsequent
chapters that can be read independently, describe particular considerations in
various different models. Some new material is presented along the various
sections.
