The spin of the nucleon from the HERMES point of view

In its 12 years of successful running, the HERMES experiment has addressed all aspects in studying the spin structure of the nucleon by measuring not only inclusive but also semi-inclusive and exclusive processes in deep-inelastic lepton scattering. Novel and pioneering results on the spin structure of the nucleon are presented which illustrate the new trends in the field. We concentrate here on the quark spin flavour decomposition of the nucleon spin, the extraction of the gluon polarisation and on novel transverse spin phenomena. The new formalism of Generalised Parton Distributions and their investigation in hard exclusive processes is discussed elsewhere at this workshop [M. Düren, Hard exclusive reactions and Generalised Parton Distributions at HERMES, proceedings to this Workshop].