A great interest for diffraction has been generated these last years by the
HERA data. They give us the first opportunity to understand high energy
diffractive physics in terms of a fundamental theory, i.e. QCD. A review of the
main results from H1 and ZEUS in this field is presented and the relation with
the proton structure function at small x-Bjorken values is discussed.Comment: 10 pages. Contribution to the Proceedings of Hadron Physics 200