Shadow is good. It's how you control and use the shadow areas in the shot that is key.
Basically, the larger the light source appears relative to the subject (apparent light size) the softer the transition between highlight (i.e. skin) and the shadow area will be.
Use a small light source compared to a human body set 10ft away - a bare speedlight for example - and the shadows will be more defined, 'harder' as it's know. But make that light source several feet across but still in the same position - 28" softbox for example - then the shadows will be gentler.
There are other differences to consider as well - how much diffusion is used and how much light that diffusion eats up.
It's worth reading something like
Strobist:101 to give an idea of what can be achieved with different bits of equipment.