Girls' Generation (Korean: 소녀시대, Hanja: 少女時代, Sonyeo Sidae ) is a nine-member South Korean girl group formed by SM Entertainment in 2007. The nine members are: Taeyeon, Jessica, Sunny, Tiffany, Hyoyeon, Yuri, Sooyoung, Yoona and Seohyun. They are often referred to as SoShi (소시, Hanja: 少時), or SNSD, the first of which is an abbreviation and the second, mainly used outside Korea, is an acronym of the group's Korean name So Nyuh Shi Dae. In China and Taiwan, they are known as 少女時代 (Shàonǚ Shídài; or Síunéuih Sìhdoih in Hong Kong) and in Japan as 少女時代 (Shōjo Jidai).
The group has released two full albums, three mini-albums, and various singles. Their 2009 hit single Gee holds the record for being the longest running #1 song on KBS's Music Bank, having held the #1 chart ranking for 9 consecutive weeks. Gee was also song of the decade by the Korean music site, Melon 2009 and 2010 also saw the group winning various awards, including consecutive Artist of the Year (Daesang) awards at the Seoul Music Awards, Golden Disk Awards, Melon Music Awards, and the Korean Cultural Entertainment Awards.
The group began a foray into the Japanese music scene in late 2010 under Nayutawave Records, a part of Universal Music, with the Japanese remakes of their 2009 Korean hits Tell Me Your Wish (Genie) and Gee. 2010 saw the group reach considerable success in Japan, in Korea after winning the prestigious Disk Daesang (Album of the Year) and Artist of the Year at the Golden Disk Awards, Seoul Music Awards, and Melon Music Awards respectively. The group was certified gold by the RIAJ five times in Japan.
source : en.wikipedia.org