Abstract
Particle production in ep collisions are sensitive to many different aspects of QCD; parton dynamics, fragmentation and hadronisation models, instantons, pentaquarks, multiple interactions, etc... What is common amongst all these studies is that QCD is unable to give exact predictions and various assumptions have to be made in order to construct models of the physics processes. I will present a brief overview of QCD and its limitations and some recent results from H1 will be presented together with a comparison to QCD models and with observations made in e+e-, ppbar and even heavy iron interactions.