Which statement describes lossless data compression?

Which statement describes lossless data compression?

• A. increases file size for speed
• B. compresses data only temporarily
• C. reduces the file size without any loss of data quality
• D. increases quality loss in exchange for speed

Answer: (C)

Lossless data compression is about shrinking a file's size while keeping every bit of information intact so the original data can be recovered exactly after decompression. The statement that describes this best is that it reduces the file size without any loss of data quality, because once you decompress, you get the exact same data you started with, with no information lost in the process. This differs from other ideas: lossless compression isn’t about making files bigger or about compressing only temporarily, and it doesn’t trade quality for speed. If quality were sacrificed, that would be lossy compression, which isn’t the case here. Examples of lossless methods include ZIP for general data and PNG for images.

Lossless data compression is about shrinking a file's size while keeping every bit of information intact so the original data can be recovered exactly after decompression. The statement that describes this best is that it reduces the file size without any loss of data quality, because once you decompress, you get the exact same data you started with, with no information lost in the process.

This differs from other ideas: lossless compression isn’t about making files bigger or about compressing only temporarily, and it doesn’t trade quality for speed. If quality were sacrificed, that would be lossy compression, which isn’t the case here. Examples of lossless methods include ZIP for general data and PNG for images.