NCT 2020 Resonance is the second studio album by South Korean boy band NCT, an unlimited group project under the management of SM Entertainment. Similar to their previous release NCT 2018 Empathy, NCT 2020 Resonance is part of the "NCT 2020" project; which saw all current NCT members from several units collaborating on a full-length release. This time, the album features all 23 members from three current units of NCT; NCT 127, NCT Dream, and WayV, while introducing two new NCT members, namely Shotaro and Sungchan. It would also be the final NCT album to feature Lucas due to his hiatus and eventual departure in 2023. The first part was released on October 12, 2020, and the second part was then released on November 23, 2020.

NCT 127 is the first fixed and second overall sub-unit of the South Korean boy band NCT, formed and managed by SM Entertainment. They originally debuted on July 7, 2016, with their debut extended play NCT #127, with an original lineup of seven members: Taeil, Taeyong, Yuta, Jaehyun, Winwin, Mark, and Haechan. Doyoung and Johnny joined the unit in December 2016, ahead of their second EP Limitless, while Jungwoo, the final member, was introduced in September 2018 ahead of their first studio album Regular-Irregular. They are known for their experimental hip hop-based music, which they refer to as "neo music", as well as their vocal and rap abilities, choreographies, and performances.