From the given text, write some important points about guitar's vibrato system

Context: A vibrato system on a guitar is a mechanical device used to temporarily change the pitch of the strings. They add vibrato to the sound by changing the tension of the strings, typically at the bridge or tailpiece of an electric guitar using a controlling lever, which is alternately referred to as a whammy bar, vibrato bar, or incorrectly as a tremolo arm. The lever enables the player to quickly and temporarily vary the tension and sometimes length of the strings, changing the pitch to create a vibrato, portamento, or pitch bend effect. Instruments without a vibrato have other bridge and tailpiece systems.

Answer: 1. A vibrato system is a mechanical component that alters the pitch of the strings on a guitar.
2. They modify the string tension at the bridge or tailpiece of an electric guitar using a regulating lever, sometimes known as a whammy bar, vibrato bar, or wrongly as a tremolo arm, to add vibrato to the music.
3. With the help of the lever, the musician can quickly and momentarily alter the tension and occasionally the length of the strings, which alters the pitch and produces effects such as vibrato, portamento, and pitch bend.
4. Vibrato-free instruments need different bridge and tailpiece systems.