The nail is formed by the matrix a boomerang-shaped structure located under the sin of the proximal nail fold and cuticle. The lunula, the white half-moon between the cuticle and nail bed is the only visible portion of the nail bed.
I cannot believe some of these ads I see in magazines and trade shows. It’s some company trying to sell me one thing or another, polish usually, but sometimes acrylic or gel. And their silly advertising