YDPP is a four-member project boy group created by Starship Entertainment and Brand New Music. They consist of MXM’s Lim Young Min and Kim Dong Hyun, and Starship’s Jeong Sewoon and Lee Kwang Hyun, all of whom were previously contestants on Produce 101 Season 2. They officially debuted on April 5, 2018.
Their name is an initialism for “Youth, Dream, Passion, Purity”.
Source: kpop wiki