zip The .ZIP file extension format is a file archive and data compression format originally developed and released in 1989 by Phil Katz. With compatible zip format software, a file or a group of files can be packed (compressed) into a single .zip archive which can later be unpacked (decompressed). The zip file archive format facilitates the distribution of multiple files as single archives particularly over the internet and networked systems. Many operating systems have native support for the file format and can usually open zip archives without the need for third party software. Microsoft windows for instance has had native support for the ZIP format since Microsoft Windows 98, similarly Apple's Mac OS includes ZIP support through its default archive file handle Archive Utility.
rar The .rar filename extension is a popular and partially open archive file format associated with the compression and decompression tool WinRAR. The format was developed by Eugene Roshal with its initial release in 1993. It, like many other archive formats, acts as the compressed data container for one or several files. The archive format can maintain the directory structure of the compressed archive even when unpacked to a directory. The RAR file format supports multi volume file compression where an archive is saved as a sequence of several files of a given size.