Definition
A lossy audio compression format that reduces file size by permanently discarding audio information deemed less perceptible. Common bitrates range from 128 kbps (low quality) to 320 kbps (high quality for consumer distribution).
In Simple Terms
The most common compressed audio format. It permanently removes data to make files smaller. Great for sharing drafts, but never use MP3 as a source for mixing or mastering—the quality can't be recovered once it's gone.
In Practice
A 320 kbps MP3 is used for music distribution on platforms that do not offer lossless delivery, providing a practical compromise between file size and audio quality.
Common Confusion
Once encoded as MP3, the discarded information cannot be recovered. Always work from uncompressed source files and encode MP3 as a final delivery step, never as a working format.