  A protostellar jet and outflow are calculated for \sim 270 yr following the
protostar formation using a three dimensional magnetohydrodynamics simulation,
in which both the protostar and its parent cloud are spatially resolved. A
high-velocity (\sim100km/s) jet with good collimation is driven near the disk's
inner edge, while a low-velocity (<10km/s) outflow with a wide opening angle
appears in the outer-disk region. The high-velocity jet propagates into the
low-velocity outflow, forming a nested velocity structure in which a narrow
high-velocity flow is enclosed by a wide low-velocity flow. The low-velocity
outflow is in a nearly steady state, while the high-velocity jet appears
intermittently. The time-variability of the jet is related to the episodic
accretion from the disk onto the protostar, which is caused by gravitational
instability and magnetic effects such as magnetic braking and magnetorotational
instability. Although the high-velocity jet has a large kinetic energy, the
mass and momentum of the jet are much smaller than those of the low-velocity
outflow. A large fraction of the infalling gas is ejected by the low-velocity
outflow. Thus, the low-velocity outflow actually has a more significant effect
than the high-velocity jet in the very early phase of the star formation.
