The term "string instruments" is used to describe musical instruments that produce sound through the vibration of stretched strings. Some common synonyms for string instruments include "plucked string instruments" which cover instruments like guitar, banjo and mandolin. Another category is "bowed string instruments" which includes the orchestral instruments like violin, viola, cello, and double bass. Other synonyms for String instruments include "fretted string instruments," "unfretted string instruments," "acoustic string instruments," and "electric string instruments." Each of these synonyms is used to express the specific type or way in which the stringed instrument produces sound. While there are various types of stringed instruments, all of them have a significant role in the world of music.