Vibrato is a technique of rapidly moving a note up and down in the direction of the adjacent strings. Vibrato is an important method of sustaining a note once it has been picked. It also gives more expression to your playing. Vibrato is often found on long notes, or a note at the end of a phrase. It is usually obtained by the movement of the wrist away from the neck and back towards the neck, much like turning a doorknob. The symbol for vibrato is a wavy line.
The following lick demonstrates the use of vibrato.