  The physics of hadron-hadron collisions is very complex involving both
perturbative and non perturbative QCD. It is imperative to study p-p collisions
in detail to provide a variety of measurements against which the theoretical
calculations can be tested. Direct jet measurements, for instance, help address
fundamental questions of the fragmentation process. They also form a critical
baseline for comparisons of results from heavy-ion studies, where fragmentation
functions are expected to be modified due to interactions with the hot and
dense medium. Finally, it is important to understand how the beam-beam
remnants, multi-parton interactions, and initial- and final-state radiation
combine to produce the particles observed in the underlying event. I present
results from p-p collisions at 200 GeV collisions as measured by the STAR
experiment.
