Girls' Generation is titled 'The Nation's Girl Group' in South Korea for their widespread popularity and achievement in the country and are also popular in Japan, other East Asian countries, and have small fan bases in the American continent and Europe. They are overall the top second generation K-pop girl group. Formed and debuted under SM Entertainment in 2007. The group is composed of eight members: Taeyeon, Sunny, Tiffany, Hyoyeon, Yuri, Sooyoung, Yoona, and Seohyun. Originally a nine-piece group. The group has sold more than 5 million physical copies combined between South Korea and Japan.
Here is a summary of their sales in both countries.