What are each wires in a 3.5 mm mini jack for.?

Question

I see a red and white, which I was expecting, but I also see a bare wire that is wrapped around the two. Is it the ground?

Answer 1

Yep, that's the ground

Answer 2

Red is the right speaker signal ,white is the left speaker signal and the bare wire is the negative or, yes, the ground. It also doubles as a shield by allowing RF(radio frequency) and EM (electro magnetic) interference to be carried to ground instead of going into the signal.