Setting and Fixing sprays for the most parts are the same (interchangeable names).
Setting/Fixing sprays focus on keeping your makeup in place. Some may have hydrating ingredients as well but it primarily contains cosmetic ingredients that keep makeup in place. Many of these products also include ingredients like alcohol and glycerin which aid in locking makeup in place.
Facial mists usually focus on skincare with hydrating ingredients, and sometimes calming or pore minimizing ingredients. Some facial mists feel just like water and can double as a toner, while other facial mists are more moisturizing and application is intended for after skincare for hydration boosts.
Keep in mind, both mists and sprays can be used to set makeup
Going back to our analogy, imagine this, you finished your painting, now it’s time to seal the deal. When you finish painting a wall (or your face, in this case), you want to add a protective layer over the pain to keep it from moving, basically laminating if you will. This is what setting spray does due to the cosmetic ingredients, promoting longer wear for your makeup.
Now with a mist, and for the purpose of our analogy, you’re basically finishing a painting and spraying water to break it down slightly and allow it to mold together, fusing it with your skin. You’re also setting makeup and hydrating but not necessarily “locking it in” due to the lack of cosmetic ingredients.
So, which product should you use?
That’s really up to you.
Many get away with setting spray because it’s more bang for your buck, however, I would advice that it can be potentially drying if it contains glycerin and alcohol.
If you want a natural refresher to lightly set makeup and give your skin and makeup a little after lunch boost, I would advice my personal choice, a mist.