  In this thesis the polarized and unpolarized photon distributions of the
nucleon (proton, neutron) $(\Delta)\gamma^N$, evaluated in the equivalent
photon approximation (EPA), are computed theoretically and the possibility of
their experimental determination is demonstrated. Both of them consist of two
components: the elastic ones, $(\Delta)\gamma^N_{\rm el}$, due to $N\to \gamma
N $, and the inelastic ones, $(\Delta)\gamma^N_{\rm inel}$, due to $N\to \gamma
X$, with $X \neq N$. Special attention is devoted to the QED Compton process in
$e N \to e \gamma N$ and $e N \to e \gamma X$, which is one of the most
important reactions for directly measuring the photon content of the nucleon
and testing the reliability of the EPA. Furthermore, it is discussed how such
measurements can provide additional, independent informations concerning the
usual polarized and unpolarized structure functions.
