What is compression?

• A. Increasing file sizes
• B. Encrypting files
• C. Defragmenting files
• D. Reducing file sizes by permanently or temporarily removing data

Answer: (D)

Compression is the process of making data take up fewer bits by encoding it more efficiently. It works by removing redundancy and irrelevancies in the data, so the resulting file is smaller. There are two main types: lossless, where the original data can be reconstructed exactly, and lossy, where some information is permanently discarded to achieve higher reductions. That’s why the idea of reducing file sizes by removing data fits best: you’re shrinking the amount of information stored or transmitted, either without losing anything (lossless) or by sacrificing some data for a smaller size (lossy). The other options aren’t about reducing size: increasing file sizes would do the opposite, encryption protects data, and defragmentation reorganizes storage without changing the total amount of data.