What do the terms 'permanent wave' and 'perm' refer to?

The terms 'permanent wave' and 'perm' specifically refer to a chemical treatment that alters the structure of straight hair to create curls or waves. This process involves the use of chemical solutions that break and reform the bonds in the hair, enabling it to take on a curly or wavy shape that lasts for an extended period.

The effectiveness of a perm lies in its ability to provide long-lasting results compared to temporary methods, which may only curl the hair until the next wash. A perm is a more durable solution, often lasting several months, and is sought after for its ability to offer volume and texture to hair.

Other options refer to hair processes that do not align with the definition of 'permanent wave.' For instance, a temporary curl method only lasts for a short duration and doesn't involve chemical changes to the hair's structure. Similarly, hair straightening processes or styling tools are not related to creating curls or waves, making them irrelevant in the context of what a perm entails.