G-string

Air on a G string -It is needless to say this is a world famous Bach's work. Those who might not have memories to listen to his work intentionally oftentimes must have listened to this music in many occasions on the street in public. Now I listen to his music again...
My question is what G string here means. You see G string is a word refers to a tiny piece of garment that covers dancer's private part in time of her dancing.
I once asked who knows how to play violin well what G string in violin means. He replied, 'G string is one of the strings in violin in which you don't have to use fingers to play it.
You don't have to use fingers to play it! Still I am not certain how to play the violin without using fingers though, I felt I was able to understand what G string means - You don't have to use fingers to cover your private part in use of G string. Of course, if I believe what he said, you don't have to use fingers to play the G string.