Why do files get smaller when zipped?
Show answer & explanation
Answer: Patterns are replaced with codes
Colors are reduced — Wrong. Zip is lossless compression—works on any file type, not just images. It finds repeated byte patterns and represents them with shorter codes.
Patterns are replaced with codes ✓ — Correct! Zip uses lossless compression algorithms (like DEFLATE). They find repeated patterns and replace with shorter references. Example: 'AAAAAAA' becomes '7A'. Huffman coding assigns shorter codes to frequent characters. Dictionary-based methods reference previous occurrences. Unzipping reconstructs original data perfectly. Already-compressed files (JPG, MP4) zip poorly—no redundancy left!
Resolution is lowered — Wrong. Zip doesn't change resolution—that's lossy image compression. Zip is lossless, finding patterns to encode more efficiently without data loss.
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