What Is Love is the title track from TWICE's 2018 EP of the same name, released by the South Korean girl group at the height of their early popularity. The song's catchy chorus and romantic theme made it a staple of K-pop fan edits and dance covers, and short clips of its hook spread widely on TikTok and YouTube Shorts. Its bright, instantly recognisable melody keeps it in circulation years later, especially in videos about crushes, first love and light-hearted romance.