The following diagram of an electric guitar reveals the names of the parts of the electric guitar that you should know. The parts in the diagram labeled in red you must know and the ones in black you should know.
The guitar I used for the diagram is a Washburn™ Paul Stanley Signature Model.
Directly below the diagram you'll find definitions of the parts, and their purposes.
Body: The body of an electric guitar is the large section of the guitar below the neck. The body amplifies the vibration of the strings when a note or chord is played. Different woods provide different tonal qualities and effect the "voice" of the guitar.
Particle board and plywood don't transmit tone as well as solid wood and makes the sound thin or tinny, and reduces sustain.
Bridge: The bridge attaches to the body and the strings get slipped through the bridge. If the guitar has a tail piece which the strings get slipped through, then the bridge acts as a support for the strings via an adjustable saddle.
Bridge Pins: There are no bridge pins on an electric guitar with the exception of an acoustic electric guitar.
Frets: The pitch of a note is caused by the frequency of the strings vibration. When the string length is shortened by being pressed against a fret it's frequency gets higher and so does the pitch of the note.
Headstock: The part of the neck above the nut where the machine heads are attached. The headstock does not affect the sound much.
Machine Heads: Machine heads are sometimes called tuning knobs or tuning buttons. They tighten or loosen the strings. Cheap machine heads can be difficult to turn or loosen the string tension quickly, or worse yet keep breaking strings because of sharp edges.
Neck: The neck is the long part from the body up.
Nut: The nut is the piece of material(bone or plastic), between the fretboard and the headstock, with grooves for the strings. See the diagram of electric guitar.
Pickups: Electric guitars have from one to three pickups. They work magnetically by changing the strings vibration frequency into sound. Each pickup produces a different tonal quality. The pickup closest to the bridge has a crisper more metallic sound, while the pickup closest to the neck has a warmer, creamier sound. If you have three pickups the one in the middle is kind of like a blend between the tonal qualities. NOTE: Good pickups can cost as much or more than a cheap guitar(hint hint)!
Pickup Selector Switch: Yup, you guessed it. The selector switch lets you choose which pickup is turned on. On some guitars you can choose a combination of two pickups.
Saddle: The saddle is the part that fits into the bridge that the strings rest across. They are usually adjustable. However if you are a beginner it is not a good idea to adjust them.
Tone and Volume Controls: These are used to adjust the volume, (usually the one closest to the neck but not always) or the tone. There is usually a separate tone control for each pickup.
Tremolo Arm or Whammy Bar: The guitar here does not have one. It is a metal handle that is attached to the bridge. When you push it in it causes the strings to slacking causing the sound to drop in pitch.
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