AirPlay, Apple's proprietary wireless streaming protocol, has been around a lot longer than you might expect. Indeed, AirTunes, the earliest incarnation of AirPlay, was launched in 2004, three years before the first iPhone even hit the market.
Apple AirPlay 2 vs AirPlay: Differences and perks explained
AirPlay 2 improves upon Apple's original AirPlay, including multi-room audio, listening to different songs on different speakers, and more.