Steam is Valve's PC gaming platform, where games award achievements for completing specific tasks, from finishing a level to finding a hidden item. Each unlock triggers this short notification sound alongside an on-screen popup, so regular players learn to associate it with progress and success. As gameplay clips and streaming grew, editors began lifting the chime out of games and placing it over unrelated moments, turning a system notification into a shorthand for any small victory. That familiarity is why it still works in memes, montages and reaction videos today.