A guitar diagram will help you understand the different parts of your instrument. Below the following diagram, you will find all the terms you need explained. If you still want more information on the guitar, don’t hesitate to contact me in the comments below.

1. Guitar Diagram
Guitar Diagram
2. Guitar Diagram Terms

Listed alphabetically:

Body: it’s the wooden part of the acoustic or electric guitar below the neck. In the diagram, the acoustic instrument has a hollow-body, and the electric one a solid-body. Note that the wood used for this part plays an important role in the guitar “tonality”.
Bridge: this little piece is here to maintain the strings at a certain height. It’s also entirely connected to the body and transmits the resonance made by the strings when played. Wooden bridges are the most common ones among acoustic guitars. But metallic bridges are preferred for electric guitars.
Fret (wire): this metallic piece divides the guitar neck into several parts named cases (or frets). These cases allow the guitarist to play ascendent notes – from 1 to 24 for example. When the string is pressed on the first case, the first fret wire replaces the nut.
Fretboard (or guitar neck): it’s the wooden part (usually hardwood) just above the body. It’s where you press the strings to change the pitch.
Head (headstock or peghead): the highest part. It’s here to hold the strings. It’s also thanks to the machine heads attached that you will be able to tune your guitar. Guitar brands are often present on it.
Nut: a piece usually made of plastic just between the fretboard and the head. It allows the string to be heighten.
Pickguard: a piece made of plastic in general. Its main goal is to protect the guitar from pick scratches but it can also be decorative.
Pickup: the metallic device placed under the strings that captures the vibrations made by the strings. It transmits them electrically to any other piece of device such as an amplifier, effect pedal, recording machine, etc (for more on pickup, go here)
Pickup switch: a little button made to allow a specific pickup to capture the sound.
Position Marker (or Inlay): basically to know where you are when you play. They’re often situated on the 3rd, 5th, 9th, 12th, 15th, 17th, 19th and 21st position.
Saddle: the saddle is fixed on the bridge and grants the strings to rest on them. It also transmits the vibrations to the bridge which pass them on to the sound board.
Sound hole: without it, your guitar would not sound as loud as it sounds. But it’s actually from the soundboard that the majority of the sound produced goes out. The sound hole is just here to accentuate the vibrations and the tone made by plucking the strings.
Tuning knobs: placed on the head, it gives you the power to tune your guitar correctly, or to change your strings.
Volume / tone knob: to increase or decrease volume (volume knob), or to filter the frequencies captured by the different pickups (tone knob).