Nails, though they feel a great deal different from a person's skin or an animal's hoof, are composed of roughly the same cellular makeup. The big contributor to this is a protein called keratin, which is what the body uses to make both finger and toe nails, as well as skin and hair. This entire process begins at the nail root. The nail root is below your skin and nail, so it cannot actually be seen. What can be seen however is the cuticle, which is the U-shaped area where the visible nail begins. The nail root is actually located beneath the lunula, Latin for moon, which is the half moon shape at the base of the nail. This half moon shape is easiest to see at the base of a person's thumbnail, and it is located directly over the nail root.
Fingernails will grow faster than toenails, so the process is most clearly seen right at our fingertips. The body is constantly producing new nail cells, which grow and form a plate at the nail root. The cells are hardened as keratin is added, and they form a flat, protective covering over the nail bed, the flat area of skin beneath your nails. As more nail cells are produced, they push out old nail cells, which lengthens a person's fingernails out longer and longer until they either break or are trimmed back. Additionally, the nail bed sits atop tiny blood vessels that nourish the nail throughout the growth process. It's these blood vessels that give the nail its healthy, pink color.
Fingernails grow at roughly the rate of 1/10th of an inch every month, or the equivalent of 2.5 millimeters. This means that taking care of your nails can be a common chore, and it should be carefully attended to in order to prevent infection and to keep the growth process going smoothly. Fingernails should be trimmed straight across and slightly rounded at the top. Any jagged edges should be trimmed off or filed away. Additionally, moisturizing the nails can often help keep them healthy.