Bitrate refers to the amount of bits – or the amount of data – a digital audio file contains per second. It’s most commonly used to convey the quality of compressed audio formats, such as MP3 or AAC, in kilobytes per second (kbps).
The higher this number, the more information that file holds and the less compressed it is. Assuming the source it originated from is a good one, more information generally translates to a better-sounding piece of music.
Spotify Premium streams at 320kbps while Apple Music streams at 256kbps. It will depend on the kit you are using as to whether you can hear a difference between the two, but the Spotify streams are, technically at least, better quality.
By comparison, if you were to break down CD quality into bitrate, it would be 1,411kbps, which shows the difference in quality between compressed and uncompressed (lossless) music.
Read more about the science of sound:
- How do amplifiers work?
- Bluetooth, AirPlay, Chromecast… Does it matter how I connect to my wireless speakers?
- Why does light travel faster than sound?
- How is sound created when two objects collide?