A permanent wave, also known as a perm, is a chemical hair treatment that can be used to straighten or add curl and body to your hair. Every perm has two parts: the physical wrapping of the hair into shapes and a chemical bath that breaks and then reforms the disulfide bonds of your hair. In other words, the chemicals soften the inner structure of the hair.
Hair perms are a fantastic way and versatile process. With today's perms, you can have everything from body to loose and sexy waves to true curls. Hair perms will also give you the true "wash and wear" hair style that every woman seeks. A hair perm can free you from the hassles of setting, blow-drying, and curling irons.
A digital perm is a perm which uses hot rods with the temperature regulated by a machine, which has a digital display, hence the name. However, the process of the perm is quite analogous to that of a traditional perm. The name "Digital Perm" is also copyrighted by a Japanese company, PAIMORE Co., Ltd. Hairstylists usually call it a "hot perm", but it is commonly known as a "digital perm".
A normal perm basically requires only the perm solution. A digital perm requires a (different) solution plus heat. This type of perm was developed in Korea.
The look is especially popular among women with long hair and traditionally straight hair types. This has made the process extremely popular in Asia and other regions where straight hair is the ethnic norm. Most digital perm machines come with a wide range of rod sizes, so virtually any permed look is possible.