Brightline is one of Samsung's built-in notification sounds, supplied on Galaxy phones as a short alert tone for messages and app notifications. Because millions of people hear it in everyday life, it has become instantly recognisable outside the phone itself, and creators began lifting it into short videos, memes and edits. It works as shorthand for a phone buzzing, a message landing or a notification interrupting a scene, without needing any on-screen text. That everyday familiarity is why it remains a popular choice for realistic phone moments.