“The guitar is classified as a plucked string instrument, or chordophone, which produces sound by creating a vibration of the strings. They can have up to 18 strings depending on the type of guitar but most only have six. The sound is produced by creating vibration in the hollow body of an acoustic guitar or through an amplifier for an electric guitar. The guitar is traditionally made of wood and the strings of gut, nylon or steel. Unlike the hollow-bodied acoustic, electric guitars typically have a solid body to prevent feedback.” –
ipassio.com