jremington:
A brushed or brushless (more expensive) DC motor can provide far more torque than a stepping motor of the same size. Few people use steppers for robot wheels or tracks.
No, not true, steppers win out in my experience. I've a 200W BLDC and it gives 0.44Nm,
whereas a NEMA23 stepper motor of about the same size is about 3Nm.
However gearmotors are able to provide almost any amount of torque since you trade
speed for torque. But you can add gears to a stepper motor too...