What is lossy compression?

• A. A method that permanently discards some original information to reduce file size
• B. A method that increases file size for better quality
• C. A method that preserves all original data but reduces size
• D. A method that duplicates data

Answer: (A)

Lossy compression reduces a file’s size by permanently discarding some of the original information. After decompression you get a version that’s close to the original but not exactly the same, because some data was removed to make the file smaller. This trade-off—larger size reduction for a small loss in quality—is common in multimedia formats like JPEG images and MP3 audio. It’s different from lossless compression, which preserves all data but may not shrink the file as much, and it’s not about increasing size or duplicating data.