Lossless compression refers to what?

• A. A method that reduces file size with slight quality loss.
• B. A method of reducing file size without losing any quality.
• C. A method that encrypts data.
• D. A method that increases file size for higher fidelity.

Answer: (B)

Lossless compression reduces the size of a file while keeping every bit of the original data intact. When the file is decompressed, you get exactly the same data as before, with no changes or losses. This is essential for types of data where any alteration would be unacceptable, like text, software, or archival images. For example, PNG images use lossless compression, so there are no visual artifacts after decompression. The other ideas describe different concepts: reducing size with quality loss (lossy compression), encrypting data (protecting it rather than shrinking it), or increasing size to improve fidelity (the opposite of compression). So the best description is that it reduces file size without losing any quality.