Collecting societies (VG) are private organizations that manage the copyrights or related rights in a fiduciary capacity for many originators or holders of related rights. The legal basis for this in Germany is the Copyright Administration Act (UrhWahrnG), which governs the authorization and work of the collecting societies. The regulatory authority is the German Patent and Trade Mark Office. A total of 13 collecting societies are currently approved in Germany (as of March 2015).

Source: Wikipedia, edited (only available in German)