  Generalized parton distributions (GPDs) offer a comprehensive picture of the
nucleon structure and dynamics and provide a link between microscopic and
macroscopic properties of the nucleon. These quantities, which can be
interpreted as the transverse distribution of partons carrying a certain
longitudinal momentum fraction of the nucleon can be accessed in deep exclusive
processes. This lecture reviews the main features of the nucleon structure as
obtained from elastic and inelastic lepton scatterings and unified in the
context of the GPDs framework. Particular emphasis is put on the experimental
methods to access these distributions and the today experimental status.
