Final answer:
The cuticles are a protective barrier overlapping the edge of the nail plate, which are important for preventing infections. They should not be cut during a manicure to avoid damaging this protective barrier and risking infection.
Step-by-step explanation:
When a manicurist works on your cuticles, they are tending to a part of your nail anatomy which serves as a protective barrier. The cuticle, or eponychium, is a layer of dead epithelial cells that overlaps the edge of the nail plate and helps to seal the edges of the nail. This helps prevent infections in the underlying tissues. The nail plate itself is composed of densely packed dead keratinocytes and it is the visible part of the nail, which you typically trim. It's important not to cut the cuticles because doing so can lead to infections and damage the protective barrier they provide. Instead, the cuticles can be gently pushed back or maintained with cuticle oil to keep them healthy.