MP3
Lossy compressed audio format. MPEG-1 Layer 3, standardized 1993. Karlheinz Brandenburg + Fraunhofer Institute. Created the digital music revolution.
Psychoacoustic compression — removes frequencies the ear doesn't perceive. 128–320 kbps typical. Driven by Napster (1999) and iPod (2001) to dominance. Patent licenses expired in 2017 → MP3 is now free. Modern codecs are better: AAC (iTunes/YouTube default), Opus (Discord, WebRTC, modern web), FLAC (lossless). MP3 lives on as the universal baseline format.