You will find information about the six levels A1 A2 B1 B2 C1 C2 here: http://en.wikipedia.org/wiki/Common_European_Framework_of_Reference_for_Languages

Hi Tim, These are ratings that are used in Europe. B1 and B2 would be along the lines of intermediate and advanced intermediate, with C1 and C2 being advanced and highly advanced. It's a scale starting with A1 being beginner and C2 being practically fluent. Hope this helps! I'm not an expert but this is how I understand it.