The Neck (nɛ́k) of a guitar is the piece of wood that extends from the guitar body and ends with the headstock. Most necks have small dots on the fretboard to signify the fret number. On custom guitars the fret markers will often be pictures or different shapes depending on the theme. Some necks are bolted on to the main body of the guitar, while others are part of the body itself. The neck is where the frets and fretboard are glued to the guitar. Attached to the headstock, are the tuning machines and truss rod. The frets are the small ridges down the neck against which the strings are pushed to form notes.