As suggested by its name, a 7-String Guitars has seven strings as opposed to the traditional six. That part, you can most likely have suspected on your own. However, you may not realize that as being a six stringed guitar, the seven string will come in a variety of styles http://legalcook68.bravesites.com/entries/general/all-you-need-to-know-about-the-7-string-guitar