Fingernails are formed by living skin cells in the fingers. They consist of multiple components: the nail plate (the visible section), the nail bed (the skin beneath the plate), the cuticle (the tissue overlapping the plate at the base), the nail folds (the skin surrounding the nail on three sides), the lunula (the pale half-moon shape at the base), and the matrix (the hidden part under the cuticle where growth occurs). The matrix is where nail growth begins, composed mainly of keratin, a tough protein found in both skin and hair. As new cells develop in the matrix, older ones are pushed out, becoming compacted into the familiar hard, flat form of a fingernail. On average, nails grow 0.1 mm per day, equating to 1 cm every 100 days. Growth rates can vary due to age, gender, and the season, with nails generally growing faster in younger people, males, and during summer months. Fingernails tend to grow at a quicker pace than toenails, and for right-handed individuals, nails on the right hand usually grow faster than those on the left, with the opposite true for left-handed people.