A guitar amplifier is an electronic device that increases the sound of an electric guitar. It takes the weak electrical signal produced by the guitar's pickups and boosts it, allowing the sound to be heard through speakers. Amplifiers come in various types, including tube amplifiers, which use vacuum tubes for warmth and richness, and solid-state amplifiers, which use transistors for reliability and clarity. Guitar amplifiers often include features like tone controls, effects, and built-in reverb to shape the sound. They can be found in different sizes, from small practice amps to large, powerful models used in concerts. Many musicians choose amplifiers based on their desired sound and playing style.