Lossy file compression causes a significant loss in data and quality compared to the original version. Lossy compression is typically associated with image files, such as JPEGs, but they are also used for audio files such as MP3s or AAC files. The “looseness” of an image file is revealed by looking at its jagged edges or pixelated areas. At the same time, even in audio files, it produces lossyness, reduces the dynamic range of a watery sound or audio.
Since data is removed from the original file with lossy compression, the last resulting file occupies much less space in the disk than if it were with the original file. For example, image size in a JPEG image is reduced by more than 80%, with a much less noticeable effect. Just like that, the size of a compressed MP3 file is also about one-tenth compared to the original audio file, but there is not much difference in their sound.
Here the keyword “almost” is used. Both JPEG and MP3 compression remove the data from the original file, which can be noted if a close examination is done. Both compression algorithms allow different types of “quality settings,” which decide how to compress the file.
The quality set includes a trade-off between quality and file size. A file that uses more excellent compression takes much less space, but it is not as good in appearance or hearing as a less compressed file. Some image and audio formats allow lossless compression, which does not reduce the quality of the file at all.