Electromagnetic form factors of the nucleon are model-independent observables which encode our ignorance of its complex internal structure. In recent years significant attention has been drawn to these observables due to the discovery of unexplained deviations from previously measured results.

Recoil polarization measurements and high precision cross section measurements are allowing the electric to magnetic form factors ratios be determined with unprecedented precision. New results from MIT-BLAST and, more recently, from Hall A at Jefferson Lab indicate that there is an unexpected decrease in the proton form factor ratio at low Q2. Even newer data is expected to come from MAINZ and JLab experiments in the near future.

Nucleon modifications in the nuclear matter have been suggested as possible explanation of different phenomena, such as the EMC effect and quenching of the Coulomb sum rule. Unambiguous evidence of these modifications has yet to be found. A sensitive probe for such modification is the ratio of the electric to magnetic nucleon form factors.

This talk will address the measurement, and interpretation, of the nucleon form factors, present new results of the proton form factors as a probe of the proton peripheral structure, and discuss the probing of the nucleon modification in the medium using measurements of the EM form factors.