When it comes to studio photography, your choice of the light modifier you use really affects the quality of light you'll get.
Basically, a light modifier is anything that can change the direction or quality of light. Even your white wall, ceiling or a cloth can be a modifier.
Above is a modifier called, the 120cm deep parabolic softbox. It is my favorite modifier when it comes to shooting beauty portrats and headshots. I love for it shade, being that deep enables the light travel far and it doesn't allow for much spread of light. To further concentrate and control the light.you can place a grid on it to further concentrate the light on your subject. Here's what a grid looks like.
It is a double diffused softbox so you can imagine how soft the light would be. Its my go to modifier anytime.
Here are images i shot with it.
My second best modifier is the 160cm parabolic umbrella.
This is bigger than the 120cm and the means the light here gets softer. I use it for full length Shots, and more creative portiats.
Light from this modifier if used properly gives more of a natural lighting feel to images. That is why i love it.
Sometimes i use it for fill, to fill up the shadows. It works really great.