Some love them, some hate them/-

The compression algorithm. Both compress files/folders into archives that are smaller than the originals (in most cases) but they use different methods to accomplish this. 7zip is a free and simple program that works with both. http://www.7-zip.org/

rar files are more complex to break if encrypted with password and rar is superior to zip!

1) Parameter differences: - "Recovery Record Many archive formats contain redundant data embedded in the files in order to detect data storage or transmission errors, and the software used to read the archive files contain logic to detect and correct errors." RAR has it, ZIP does not mention it. - "Unicode filenames" RAR has it, but ZIP does not have it. Source and further information: http://en.wikipedia.org/wiki/Comparison_of_archive_formats 2) "In computing, RAR is an archive file format that supports data compression, error recovery, and file spanning." "RAR compression operations are typically slower than compressing the same data with early compression algorithms like ZIP and gzip, but with a moderately better rate of compression." "WinRAR is the only graphical tool for Microsoft Windows which can read and write modern RAR files. Its command line equivalent, RAR, is available for Windows, Linux, Mac OS X, MS-DOS, OS/2 and FreeBSD. Additionally, the unrar tool from the same distributor can be used on the aforementioned platforms to extract RAR files but not to write them. Third party programs for Windows which can read RAR files include 7-Zip, IZArc, PeaZip and Zipeg, along with the free version of unrar (which is also available for Linux and FreeBSD). Mac OS X readers include Stuffit Expander, The Unarchiver and Zipeg." Source and further information: http://en.wikipedia.org/wiki/RAR 3) "The ZIP file format is a data compression and archival format. A ZIP file contains one or more files that have been compressed, to reduce their file size, or stored as-is. A number of compression algorithms are permitted in zip files but as of 2008 only DEFLATE is widely used and supported. The format was originally evolved by Phil Katz for PKZIP from the previous ARC compression format by Thom Henderson. However, many software utilities other than PKZIP itself are now available to create, modify, or open (unzip, decompress) ZIP files, notably WinZip, BOMArchiveHelper, StuffIt, KGB Archiver, PicoZip, Info-ZIP, WinRAR, IZArc, 7-Zip, ALZip, TUGZip, PeaZip, Universal Extractor and Zip Genius. Microsoft has included built-in ZIP support (under the name "compressed folders") in later versions of its Windows operating system. Apple has included built-in ZIP support in Mac OS X 10.3 and Mac OS X 10.4 via the BOMArchiveHelper utility, now called Archive Utility in Mac OS X 10.5 . The zip, zipcloak, zipnote, zipsplit tools are used widely in unix-like systems." Source and further information: http://en.wikipedia.org/wiki/ZIP_(file_format%29

Rar is more safe and highly compressed than Zip

none in use; only in storage format. Both are archive formats, both are window, linux and mac compatable and both are shareware.

The compression algorithm that is used. Other than that, they're the same. In most cases you'll probably find the 7z algorithm better than either.