A perm, short for permanent wave, is a chemical treatment used to create curls or waves in hair. The process involves applying a chemical solution to the hair, which breaks down its natural structure, allowing it to be reshaped around rods or curlers. Once the desired curl pattern is achieved, a neutralizer is applied to set the new shape. Perms can vary in size and tightness, from loose waves to tight curls, depending on the rods used and the technique applied. This hairstyle can last several months, making it a popular choice for those looking to add volume and texture to their hair without daily styling.