A fret is a slightly raised strip of metal, or the space between any two adjacent such strips, precisely embedded in the fingerboard on some stringed instruments, such as guitars, lutes and ukuleles, with each fret representing one semitone. They are usually made of a hard nickel-iron alloy and their number can range from about twelve to 20 in the case of guitars. Pressing a string against a fret shortens the vibrating length of the string, thereby reducing the pitch. Frets make it easier to play notes and chords accurately, as compared with violins and other fretless stringed instruments.