The QCD description of diffractive processes

Abstract
We review the application of perturbative QCD to diffractive processes. We introduce the two-gluon exchange model to describe diffractive and production in deep inelastic scattering. We study the triple Regge limit and briefly consider multiple gluon exchange. We discuss diffractive vector meson production at HERA both at t = 0 and large |t|. We demonstrate the non-factorization of diffractive processes at hadron colliders.