Compression

How ZIP Files Compress Data and When They Save Space

A ZIP file can turn a folder containing many files into one convenient archive, and that archive may take up less space than the originals. Sometimes the reduction is dramatic. Other times, a large collection barely becomes smaller at all. The difference is not random. ZIP compression works by finding patterns that can be represented more efficiently. Whether it saves much space depends largely on how much reusable structure remains in the files being compressed.