GreenDay are an American rock band that formed in 1986. The band consists of lead vocalist and guitarist Billie Joe Armstrong, bassist and backing vocalist Mike Dirnt, and drummer Tré Cool. Green Day is known for its punk rock sound, catchy melodies, and socially relevant lyrics. They rose to prominence in the early 1990s with their third studio album, "Dookie" (1994), which became a major commercial success.

This album, featuring hits like "Basket Case" and "When I Come Around," played a significant role in bringing punk rock to mainstream audiences. A rock opera that addresses political and social issues, "American Idiot" became one of Green Day's most successful and critically acclaimed albums. The title track and "Boulevard of Broken Dreams" are among its standout songs. Another rock opera, this album explores the lives of two characters named Christian and Gloria against a backdrop of political and social turmoil. It features tracks such as "Know Your Enemy" and "21 Guns."

Green Day has had a significant impact on the punk rock and alternative music scenes and has been recognized with numerous awards, including Grammy Awards. Beyond their music, the band has been involved in various social and political causes.