The experimental and theoretical investigation of nucleon-nucleon collisions at high energies allows to explore the structure of the nucleon by large momentum transfer (deep-inelastic) processes. In these lectures the structure of the nucleon from momentum scales Q > 1 GeV/c (<0.1 fm) to Q ∼ 100 GeV/c (≤ 10-16cm) is discussed. In the first lecture the basic concepts of the parton model and of perturbative quantum chromodynamics (QCD) are introduced, and applied to deep inelastic lepton- nucleon scattering. The following lectures cover large transverse momentum, pT′, hadronic processes, massive dilepton production and production of prompt real photons at large pT° The present status of the theoretical understanding of these processes is summarized. Because of the enormous amount of work performed in this field of research during the past years completeness is impossible to pretend. Nevertheless, together with the lectures by J. Strauss [1] on the recent CERN \(\rm Sp\bar{p}S\) collider results I hope that a comprehensive overview is gained.