There are 4 parts that define the feel and shape of the guitar neck. They are depth, width, radius (curvature of the fretboard) and profile. The profile is the shape of the neck. The profiles are named after the letters C, D, U and V due to the shapes of the necks resembling these letters. The shapes can often have variations such as ‘Hard V’ or ‘soft V’. The C shape is the most common neck shape and is found on most Fenders. Gibson guitars usually have D shape necks whilst guitarists looking for a fast neck for ‘shredding’ will be better off with a U shape neck. V shape necks are more suitable for guitarists that usually play with their thumb over the neck.