What does the term "permanent wave" refer to?

The term "permanent wave" refers to a chemical treatment designed to alter the structure of hair, creating lasting curls or waves. This process involves the use of specific chemical solutions that break down the disulfide bonds in the hair. Once these bonds are broken, the hair can be reshaped around curlers or rods to achieve the desired curl pattern. After the hair sets in this new shape and the chemicals are neutralized, the disulfide bonds are reformed, resulting in a long-lasting wave or curl that can withstand normal washing and styling. This distinguishes it from other hair processes, as permanent waves are specifically aimed at providing enduring texture rather than temporary styling achieved through heat or color changes.