  We present the experimental status of electromagnetic hadron form factors.
New and surprising results, based on polarization measurements, have been
recently obtained for the electric proton and neutron form factors. In
particular, the electric and magnetic distributions inside the proton appear
not to be the same, in disagreement with results extracted from the unpolarized
cross section, using the Rosenbluth separation. The new findings have given
rise to a large number of papers and different speculations, as they question
directly the models of nucleon structure and the reaction mechanism itself
(based on $1\gamma$-exchange), with a possible revision of the calculation of
radiative corrections, two-photon contribution etc. New data in time-like
region are also available, through annihilation reactions. A large interest in
this field arises, due also to the possibility of new measurements in polarized
electron nucleon elastic scattering at JLab, and also in the time-like region,
at Frascati and at the future FAIR international facility.
