A guitar's frets, fretboard, tuners, headstock and truss rod, are all attached to a long wooden extension, the Neck. The wood used to make the fretboard usually differs from the wood in the rest of the neck. The bending stress on the neck is considerable, particularly when heavier gauge strings are used, and the ability of the neck to resist bending is important to the guitar's ability to hold a constant pitch during tuning or when strings are fretted. Some aspects to consider in a guitar neck may be the overall width of the fretboard, scale, the neck wood, the type of neck construction and the shape of the back of the neck.
Rocky visiting Central America in October of 2013 took this video of the Honduran Mahogany Guitar Necks being made. These are 3'' x 4'' x 30''. Rocky explains that the 4'' side is flat sawn and the 3'' side is quarter sawn.