Virtual Compton Scattering at Low Energy and the Generalized Polarizabilities of the Nucleon o

Virtual Compton Scattering on the nucleon: $\gamma^* N \to \gamma N$ is a new and rapidly developing field at low and high energies. This lecture is about the low energy part, i.e. for energies in the $(\gamma p)$ center-of-mass mainly up to the $\Delta(1232)$ resonance region. I review the concept of Generalized Polarizabilities of the Nucleon, and the experiments dedicated to their measurement.