YSO Jets and Molecular Outflows: Tracing the History of Star Formation

Collimated outflows from Young Stellar Objects (YSOs) can be seen as tracers of the accretion powered systems which drive them. In this paper I review some theoretical and observational aspects of YSO outflows through the prism of questions relating to the protostellar source. The issue I address is: can collimated outflows be used as ``fossils'' allowing the history of protostellar evolution to be recovered? Answering this question relies on accurately identifying where theoretical tools and observational diagnostics converge to provide unique solutions of the protostellar physics. I discuss potential links between outflow and source including the time and direction variability of jets, the jet/molecular outflow connection, and the the effect of magnetic fields. I also discuss models of the jet/outflow collimation mechanism.