For any guitar player, it is important to know the proper terminology for the various parts of a guitar’s anatomy.
Headstock – The headstock lies at the end of the guitar’s neck. The purpose of the headstock is to support the tuners, which terminates the strings of the instrument. The tuners are attached to tuning pegs and this allows the guitarist to lower or raise the pitch of the string. A secondary purpose of the headstock is identification; many guitar manufacturers use a distinctive headstock shape, often in combination with a logo and model information.
Tuning Pegs – Tuning pegs are used to raise and lower the pitch of the strings. Acoustics usually have two rows of three pegs; which when the guitar is held as normal presents one row at the top of the headstock and one row at the bottom. Electric guitars may have tuning pegs in a single row running along the top of the headstock (Fender Stratocaster) or use the the acoustic guitar layout (Gibson Les Paul).
The tuning pegs act as string terminators and it is essential for tuning stability that they suffer no defects. Tuning pegs that are misaligned, have play or excessive resistance to turning may need replacing or repair. Tuning pegs can be mounted to a plate (three on a single plate for acoustics) or be attached to the headstock as individual pegs (Fender Stratocaster); both designs rely on small screws to fix the pegs (or plate) to the headstock. Due to the tension of the strings and the constant turning of the pegs these screws may loosen; it is recommended that you check that they are screwed in tightly though never over-tighten which may in itself cause alignment problems or damage to the screw head.
Nut – All strings pass through a nut at the headstock end of the fretboard. Its function is to maintain correct string spacing and alignment so that the strings feed into their respective tuning pegs. On acoustic guitars the nut and saddle are usually made of the same material. Electric guitars commonly use plastic or synthetic nuts though sometimes metal is used. As tremolo bars can cause tuning problems, guitars equipped with them usually have some manner of locking nut, where the strings are clamped down.
Neck – The neck can be a single piece of wood or several pieces glued together and cut to shape. The fretboard is a seperate piece of wood that is attached to the neck. Necks can be glued to the body (set neck) or bolted on. Set necks are usually found on acoustic guitars and many other instruments; including the violin, lute and cello. The bolt-on neck is a design feature of electric guitars. Most necks are wood though alternative materials, such as carbon fibre composites, have been used.
Fretboard & Frets – The fretboard (or fingerboard) is a piece of wood that is glued to the front of the neck. These are commonly made of rosewood though other hard woods, such as ebony for classical guitar fretboards, may also be used. Embedded in the fretboard are a number of metal frets (fret-wire) usually numbering 20 to 24. Strings are pressed down behind a fret which changes the length of string that is free to vibrate therefore producing a different note. A simple demonstration is to be found on the 12th fret. On all guitars this is the fret that divides the string exactly in half and produces a note an octave higher than the open note. Any open string that maintains its original tension and is halved produces its octave; the same principle applies to all stringed instruments including the piano and violin.
There are a variety of fret designs. Jumbo frets are higher and wider than normal frets and require less fretboard contact to sound a clear note. Medium frets are closer to the board and must be firmly in contact with the fretboard to sound a clear note. Some guitarist prefer jumbo frets due to the ease with which you can bend strings and the faster play offered by less fretboard contact. As with many design elements of the guitar this is a subjective area that is more personal preference rather than advantage. Good technique is not dependent on fret size
The first fret is the one nearest the nut. Some manufacturers (notably Gibson) place a “zero” fret immediately after the nut which maintains good intonation and action on flatter fretboards and wider necks. The strings sit on the zero fret therefore bringing the sound of the open string nearer to the quality of a fretted note.
Most fretboards have decorative inlays on the 3rd, 5th, 7th, 9th and 12th frets which serve as markers for the guitar positions. Fetboard inlays can be highly decorative or simple shapes. On more expensive guitars they are usually made of mother of pearl or abalone.
Body – The body of a guitar consists of a treble or upper bout and a bass or lower bout. The waist is the narrow section that divides them.
The body is one of the most important factors in determining the overall tone of a guitar. It provides the resonance that shapes the tonal qualities. It determines the volume of acoustics and affects the sustain of electrics. The resonance is affected by the type of wood used, whether the body is made from layered (ply) woods or a single piece, whether it is hollow or solid and the shape and size
The woods listed below are used in the construction of both the acoustic and the electric guitar.
Bridge – The bridge is found on the lower bout of the body and its function is to allow the strings to sit at a relative height to the fretboard. Depending on the guitar, the strings may terminate at the bridge or just pass over it. On electric guitars the bridge can be raised or lowered; using two screws (thumbscrews which can be rotated with the fingers or traditional screws requiring a screwdriver) at either end of the bridge.
Content Credit: http://en.wikibooks.org/wiki/Guitar/Anatomy_of_a_Guitar