  Present data on the partonic content of the photon from LEP, TRISTAN and HERA
accelerators are reviewed and the essential aspects of the underlying ideas and
methods are pointed out. Results of the unpolarized photon structure function
F_2 from DIS_{e gamma} experiments and on large p_T jet production processes in
the resolved gamma-gamma collisions are presented for both real and virtual
photons. The results of analysis of the hadronic final state accompanying the
DIS_{e gamma} measurements, showing some discrepancies with the Monte Carlo
models, are collected together and presented as a separate issue. Also results
on the DIS_{e gamma} with leptonic final states are shown. The results from
resolved real and virtual photon processes at HERA collider based on the single
and double jet events, also charged particles and prompt photons, are
presented. In the context of virtual photon processes the data for forward jet
and forward particle production are included. In addition a short presentation
of the recent data on the heavy quark content of the photon is given. Related
topics - the polarized (spin dependent) structure functions for the real and
virtual photon, the structure function of the electron and the photonic content
of the proton are also shortly mentioned.
