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Jets and outflows are integral parts of the physical processes that form the protostellar systems. We review the characteristics of these enigmatic powerful phenomena that constitute telltale signs of the underlying fundamental physics revealed by generations of radio and optical telescopes. We highlight the breakthrough advances in theoretical understanding of the formation, thanks to the unprecedented revelation of the fine delicate structures. Kinematic and morphological theoretically predicted features of jets, winds, and outflows are extracted and favorably compatible with observational data down to sub-arcsec resolutions. The systematics of coupled nested velocity and emission components spans from Class 0 to II jet–outflow systems in molecular and atomic lines, whose ubiquitousness is naturally explained.