Final answer:
No-Stem Curls create tight, firm, and long-lasting curls with minimal mobility, often used in permanent hairstyles that last several months.
Step-by-step explanation:
Pin curls that produce tight, firm, long-lasting curls and allow for minimum mobility are known as No-Stem Curls. These curls are achieved by wrapping the hair flat against the scalp with no elevation or lift, which results in a tight, long-lasting curl with minimal mobility. This curling technique is often used in creating permanent hairstyles or perms, which are set styles in the hair that can last for several months.