Software Architect's Handbook

Lossy compression

If a lossy compression algorithm is used, some of the bytes from the original file will be lost when the file is decompressed. For a file in which you can afford to lose some bytes, you can achieve a smaller file size as compared to using a lossless compression algorithm.

This type of compression works well with images, video, and audio because the loss of redundant information may be acceptable. There are different degrees of lossy compression, and how aggressive you are with the optimization depends on the trade-off you are willing to make between file size and quality. In some cases, you can use lossy compression and there will be no perceptible difference to the user.

Joint Photographic Experts Group (JPEG) is an example ...