Buy the book 'Light, Science and Magic' and work your way through it and doing lighting like this is fairly simple.
Also, there are likely a dozen different ways to get this shot.
But if pressed, I would say... sofbox (likely), camera right, as Derrel said, above the subject, probably at a 45 degree in both the off-center and above. It's fairly small or far away as you're not getting a lot of spill around the (frame-)left side of the subject.
The modifiers on the light might be misleading only because that type of surface shouldn't be prone to specular highlighting which you'll see with a smaller light source. This also makes it very difficult to ascertain the light shape (octagonal, square, round). Looking at the falloff it could be done with a bare head or a large snoot. It's certainly controlled so there's likely something containing the splashback frame-right (scrim, barndoors, etc).