I'm relatively new to playing guitar, so sorry if this a dumb question, but what is the difference between a 12 string and a regular 6 string guitar (beyond what the name would imply)? Are all 12 strings independent? I've never seen one up close but it looks like the strings are somehow "layered", but I can't tell for sure. Does it just allow you to play a wider range of notes, or more notes at once?