Sulfates are chemical compounds you will find in many of your products at home - toothpaste, dish washing liquid, and body washes. They can even be in your trusty shampoo.
Sulfates are used in product formulations because they are great at removing residue and oils. That may be great for your pots and pans, but not your hair. Sulfates can strip your hair of the moisture it needs and textured hair can be harshly stripped of its natural oils. Do you want that to happen?