Frequency in audio files

[vincente13]

What is the difference between a mp3 file that has frequency 22100 hz and 44100hz?

Appreciate any advice

[GodofaGap]

(I think you mean 22050 Hz)

The difference is sampling accuracy. The number reflects the amounts of samples used each second to store the audio. Following the Nyquist-Shannon theorem (which states the maximum frequency that can be stored is half the sampling rate) and considering that humans can hear roughly up to frequencies of 20 kHz, normally 22050 Hz is not enough to sample an audio signal for humans, unless it doesn't contain any high frequencies.

So the difference is the frequency range that can be stored and this difference should be quite noticeable with a lot of audio signals.