Girls' Generation is composed of people.
Girls' Generation . The group is composed of eight members : Taeyeon , Sunny , Tiffany , Hyoyeon , Yuri , Sooyoung , Yoona , and Seohyun . Kim Tae-yeon ( born March 9 , 1989 ) , referred to monomously as Taeyeon , is a South Korean singer . Kwon Yu-ri ( born December 5 , 1989 ) , better known by the mononym Yuri , is a South Korean singer and actress . Seo Ju-hyun ( born June 28 , 1991 ) , known professionally as Seohyun , is a South Korean singer and actress .