Svenska Tonsättares Internationella Musikbyrå (STIM) is a non-profit Swedish collecting society for songwriters, composers and music publishers. They monitor their members’ economic rights according to the Swedish Copyright Act. STIM is also part of the worldwide network of corresponding organizations, which allows them to remunerate all creators whose music is play—even creators from other countries. In addition, STIM makes an effort to emphasize the importance of Democracy: Writers, composers and music publishers affiliated to STIM can become full voting members of the Society. This gives you the right to attend and vote at STIM's annual general meeting.
Music Publishing is the business of protecting and promoting song copyrights and collecting the royalties that these copyrights generate. Think of a song as intellectual property (it's an original piece of art!), and music publishing as the business that makes sure that songwriters get paid a fair compensation when their intellectual property is used by companies. Those companies could be record labels (mechanical royalties), radio stations, bars, and restaurants (performance royalties), or film studios and advertising agencies (sync license fees), and many more.