I didn't know you wanted technical:
Studs and bolts are made from the same strength material for given clamp load designs. Studs allow for easier installation of components since they provide something to hang parts on, which bolts can't do, not being there until after installation. Differential carriers are a good example of this. If the stud is unthreaded for a portion of its diameter, the increased shank diameter adds to the theoretical shear capacity, in the area of a joint, such as the knuckle housing to steering arm joint. Theoretically, in a threaded casting, a stud, not requiring removal and installation, would tend to wear the internal threads less, since it's only installed and stretches the threads once. In practice, this is less than a certainty.
HTH