The bow is one of the oldest known projectile launchers, the only older weapon being possibly the sling. The act of using a bow is known as archery. Typically a basic bow is comprised of a pair of curved elastic limbs, typically of wood, connected by a string. A notched projectile, an arrow, is put in place and the string is then drawn back to maximum tension. Releasing the string causes the arrow to fly through the air to its intended target.