  The physics of hadron-hadron collisions is very complex involving both
perturbative and non-perturbative QCD. It is therefore imperative to study p-p
collisions in as much detail as possible to provide a wide variety of data
against which the various theoretical calculations can be tested. Direct jet
measurements, for instance, help address fundamental questions of the
fragmentation process. These measurements form a critical baseline for
comparisons of results from heavy-ion studies, where modifications of the
fragmentation functions are expected due to interactions of the high ${Q^2}$
scattered partons with the hot and dense medium. Finally, it is also important
to gain a deeper understanding of how the beam-beam remnants, multi-parton
interactions and initial- and final-state radiation combine to produce the
particles observed in the underlying event. In this talk we present results on
jet production and the underlying event in p-p collisions at 200 GeV collisions
as measured by the STAR experiment at RHIC.
