It’s a song by South Korean girl band I.O.I (아이오아이).
“Dream Girls” is the title track from their debut album titled Chrysalis.
It is a trap pop dance track produced by Famousbro and Paul, who also composed the album intro “I.O.I”. “Dream Girls” was penned by Famousbro with rap parts written by members Lim Na-young and Choi Yoo-jung, both members also wrote the lyrics of “I.O.I”.

The song was chosen by the members themselves through a blind voting, where the members picked their album’s title track by listening to over 30 songs from famous producers.

YMC Entertainment affiliates stated that the members chose their title track and other tracks included in the album without knowing the producers and were told to pick songs that ‘match the team’.