What is data compression and how do lossless and lossy compression differ?

What is data compression and how do lossless and lossy compression differ?

• A. Compression always preserves the exact original data.
• B. Lossy compression preserves the exact original data.
• C. Lossless compression preserves the exact original data, while lossy compression discards some data for higher reduction.
• D. Both lossless and lossy achieve the same data size.

Answer: (C)

Data compression reduces the size of data by encoding it more efficiently. In lossless compression, the original data can be reconstructed exactly from the compressed form, so every bit is preserved. This is essential when exact fidelity matters, such as text files, software, or datasets. In lossy compression, some information is discarded to achieve much higher reductions in size, which means you trade perfect fidelity for smaller files—this works well for images, audio, and video where small quality losses are often acceptable. Since lossy data can’t be recovered to its original form, the correct principle is that lossless preserves the exact original data, while lossy discards some data for greater compression.

Data compression reduces the size of data by encoding it more efficiently. In lossless compression, the original data can be reconstructed exactly from the compressed form, so every bit is preserved. This is essential when exact fidelity matters, such as text files, software, or datasets. In lossy compression, some information is discarded to achieve much higher reductions in size, which means you trade perfect fidelity for smaller files—this works well for images, audio, and video where small quality losses are often acceptable. Since lossy data can’t be recovered to its original form, the correct principle is that lossless preserves the exact original data, while lossy discards some data for greater compression.