Acid perms are a type of hair perm that use a milder acid solution to create curls or waves in the hair. Unlike alkaline perms, which can be harsher, acid perms are gentler and better suited for color-treated or damaged hair. They typically produce softer, more natural-looking curls that last for several months. The process involves applying an acid-based waving solution to the hair, followed by wrapping the hair around rods. After a set period, a neutralizer is applied to lock in the curls. Acid perms are popular for their ability to provide a more flexible and manageable curl pattern, making them a preferred choice for many individuals.