The MP3 files make use of lossy compression because they want to reduce the size of the file by removing those things which are unwanted and saving space.
This compression also believes that you can remove those things which are not heard by the human ear in the audio.
This is the reason why they are so much smaller in size compared to other audio files.
The term lossy means that the removed data is discarded and is removed it is commonly used in MP3, AAC, and WMA.
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