Energy dependence of hadronic observables in the SPS energy range.

In the recent years a wealth of data on particle production
in heavy ion reactions in the beam energy range between
10 - 160 AGeV has been accumulated. I would like to give
a short overvies on the experimental situation and to discuss
what can be learned from the excitation function of hadronic
observables. This will include longitudinal and transverse spectra
as well as particle yields with a special emphasis on strange
particles.