The use of lighting is a studio is important because it is an environment that the photographer can control, this means that the photographer can get the desired effect.
This is broad lighting and is when the photographer wants to illuminate only one side of the subjects face and sometimes they will use a reflector panel to give some light to the other side but the main focus is on the side with the most light hitting it.
Here is an example:
In this photo the photographer has placed the light source to the left of the subject and then has no reflector to his right.
My Response:
I put my subject into the centre of the frame and then put a light with a diffuser to my right and then had no reflector.