A zip folder is a compressed version of a computer's file folder. It appears as a file with a .zip extension and contains files or folders that have been reduced in size using lossless data compression. The contents of a zip folder may be extracted to the hard drive so that they can be used according to their intended purposes.
A zip folder exists as a file in a computer hard drive and usually appears with a zipper-containing icon. Files of this format can be transferred between computers just like any other file type. Each zip folder can hold many files and subfolders, and each of its contents may be compressed in varying methods and degrees. The individuality of the files and folders inside a zip folder allows for single-file extraction or addition of new files without the need to recompress the entire file archive.
Past iterations of zip folders were created using external software, most notably PKZIP and WinZip. Microsoft Windows has integrated support for zip folders, including creation and management, and calls them compressed folders. Apple has likewise included zip folder support starting with Mac OS X 10.3.
A zip folder needs a minimum of 22 bytes of files inside it and can hold a maximum of 4 GB minus 1 byte. A higher-capacity zip folder called ZIP64 can carry up to 16 exbibytes, or roughly 18.4 million terabytes of data.