NCT Dream is the third sub-unit of the South Korean boy group NCT, formed by SM Entertainment in 2016 then as the teen-aged unit of NCT, later evolved away from their youth image and was re-branded in 2020 when the members became adults. The group debuted on August 25, 2016 with the single "Chewing Gum", with seven members Mark, Renjun, Jeno, Haechan, Jaemin, Chenle, and Jisung, then at an average age of 15.6 years old. NCT Dream has been internationally recognised as among the most notable teen-aged artists of their time, known for music reflecting the growth of the youth. The narrative of their title tracks have conveyed thoughts following different stages of adolescent development, with transition from innocence to rebellion and growth. So far, NCT Dream have released four extended plays, six singles, and headlined one international tour in Asia. Commercial success of their 2019 EP release We Boom turned NCT Dream into one of the top 10 best physical sellers of South Korea in 2019 and earned them Bonsang Awards at the 34th Golden Disc Awards and 2020 Seoul Music Awards. Although NCT Dream was initially formed to follow an aged-based admission-graduation system in which members would move on from the unit after reaching the Korean age of 20 (19 internationally), in 2020 SM Entertainment announced the admission-graduation system to be removed, with previously graduated member Mark set to return, and NCT Dream will continue future activities as a flexible-style group with the seven original members. The announcement was followed by over half a million copies pre-ordered for their fourth Korean EP, titled Reload, which was released in April 2020 to mark the shift in their concept. NCT Dream is the first and only Asian artist to have appeared three times consecutively on Billboard's "21 Under 21" list, in 2018, 2019 and 2020, at #20, #13 and #19 respectively, chosen for their industry impact on sales, streaming and social media. In 2018, when Time compiled a list of "25 Most Influential Teens" of the year, all members of NCT Dream were featured, highlighting their connection - as teenagers - to teenagers. They were the only Korean artists on both lists.