Twins is the eponymous debut studio album of South Korean boy band Super Junior 05, now known as just Super Junior. It was released on 5 November 2005 by in SM Entertainment. It includes their first #1 radio single, "Miracle" and debut single, "Twins (Knock Out)". The album sold over 100,000 till now. It peaked at 3rd on the MIAK K-pop albums chart, selling 28,536 copies in the first month of release.

After achieving critically acclaimed success for their debut performance of the single "Twins (Knock Out)," which was performed on SBS's Popular Songs on November 6, 2005 for the first time, the group was scheduled to release an official single of the song. However, a digital single of "Twins (Knock Out)" was released instead with three more brand new singles available for download on November 8, 2005.

The full album, which included all of the singles in the "Twins (Knock Out)" digital release and several other new tracks, was released on December 5, 2005 in South Korea.

On February 12, 2006, Super Junior started to promote their second promotional single for the album "Miracle". The performance version of the single differs from the one released in the album as the performance single has an added dance break and vocal bridge in the song. In contrast to the edgy, rock-influenced feel of "Twins (Knock Out)", "Miracle" is a light bubblegum pop love song with light-hearted dance choreography. It was the second and last song to be promoted from the album.

Only twelve of the thirteen members of Super Junior are featured in this album as Kyuhyun was not added to the group until six months after this album's release.

The album's first single, "Twins (Knock Out)" is a rap rock release. Featuring eagle-like dancing, the dance choreography arranged for the song became warmly welcomed and extremely popular. The follow-up single, "Miracle", is a typical K-pop bubblegum pop song, a genre still very welcomed by children and young adults. Like the song itself, the dance choreography for the single is also simpler and softer. The rest of the tracks in their first studio album mainly consist of pop love ballads and also R&B-influenced dance tracks with rap and fast drum beats.

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