Guitar strings are strung almost parallel to the neck, whose surface is covered by the fingerboard (fretboard). By depressing a string against the fingerboard, the effective length of the string can be changed, which in turn changes the frequency at which the string will vibrate when plucked. Guitarists typically use one hand to pluck the strings and the other to depress the strings against the fretboard.
Traditionally the dominant hand is assigned the task of plucking or strumming the strings. For the majority of people this entails using the right hand. This is because musical expression (dynamics, tonal expression and colour etc) is largely determined by the plucking hand, whilst the fretting hand is assigned the lesser mechanical task of depressing and gripping the strings. This is similar to the convention of the violin family of instruments where the right hand controls the bow. A minority however believe that left-handed people should learn to play "conventional" guitars strung in the manner used by right-handed people, simply to standardise the instrument.
The strings may be plucked using either fingers or a plectrum (Guitar pick).The sound of the guitar is achieved either mechanically or electronically, forming two main categories of guitar: acoustic (mechanical amplification) and electric (electronic amplification).
* In acoustic guitars, string vibration is transmitted through the bridge and saddle to the sound board. The sound board, typically made of a light springy wood such as spruce, vibrates the air, producing sound which is further shaped by the guitar body's resonant cavity.
* In electric guitars, transducers known as pickups convert string vibration to an electronic signal, which in turn is amplified and fed to speakers, which vibrate the air to produce the sound we hear.