A fretboard is a fingerboard on fretted stringed instruments, usually divided into semitones by raised frets. Stopping a string (holding it down against a fret) will shorten the string and make it sound at a higher pitch than if it were played open or unstopped.
Fretboards may be plain with simple markers for special positions (usually 3, 5, 7, 9 or 10 and 12) or may be elaborately decorated with inlaid mother of pearl. Often the grade of instrument could be told from the fretboard inlay.
One particularly popular pattern especially in 5-string banjos is the Tree of Life.