What is lossless compression?

• A. Removes metadata only
• B. Goes through irreversible steps
• C. Increases file size
• D. Reduces file size while retaining all original data and quality

Answer: (D)

Lossless compression shrinks a file but preserves all original data, so when you decompress it you get an exact replica of the original. No information is lost, which is why the quality stays identical. This is different from lossy compression, which discards some data to achieve higher reductions in size. So the statement that describes reducing file size while retaining all original data and quality captures the essence of lossless compression. Real-world examples include PNG images, ZIP archives, and FLAC audio, all of which can be restored to their exact original form. Use lossless when every detail matters or when the file will be edited later.