In computing, RAR is a proprietary file format, a lossless compression algorithm used for data compression and archiving, developed by the Russian software engineer Eugene Roshal. RAR uses a compression algorithm based on the LZSS which, in turn, is based on the LZ77, Thomas James Storer and Szymanski (1982). The dictionary size can vary between 64k and 4 Mb. The RAR is slower than ZIP, but has a higher compression ratio. RAR Another feature is that it has a better ZIP data redundancy. The format also allows what is known as a solid compression for compressing several files together, so that a single dictionary applies to all information, so that the compression is greater.
.ZIP is an archive file format that supports lossless data compression. A .ZIP file may contain one or more files or folders that may have been compressed. The .ZIP file format permits a number of compression algorithms. The format was originally created in 1989 by Phil Katz, and was first implemented in PKWARE, Inc.'s PKZIP utility, as a replacement for the previous ARC compression format by Thom Henderson. The .ZIP format is now supported by many software utilities other than PKZIP. Microsoft has included built-in .ZIP support (under the name "compressed folders") in versions of Microsoft Windows since 1998. Apple has included built-in .ZIP support in Mac OS X 10.3 (via BOMArchiveHelper, now Archive Utility) and later. Most free operating systems have built in support for .ZIP in similar manners to Windows and Mac OS X.