A MiniDisc player is a portable audio device that plays music stored on MiniDiscs, a small, magneto-optical disc format developed by Sony in the early 1990s. MiniDiscs can hold up to 80 minutes of audio and offer features like digital recording and editing, making them popular for personal use and professional applications. The MiniDisc format was designed to provide high-quality sound and was a competitor to other formats like CDs and MP3 players. Although it gained a dedicated following, the rise of digital music and streaming services led to its decline in popularity by the early 2000s.