super junior and girlsgeneration are well known group from south korea formed by sm entertaiment..
S.M. Entertainment (Hangul: SM엔터테인먼트) is an independent Korean record label, talent agency, producer, and publisher of pop music, founded by Lee Soo-man in South Korea. Initially, "SM" was an abbreviation of the agency founder's name, but now stands for "Star Museum." Its current CEO is Kim Young-min. The label is one of the "big three" record companies of Korea along with YG Entertainment and JYP Entertainment because of strong market share and international operations, they lead and started the Hallyu wave.