It is an archive file format which supports error recovery, data compression and file spanning. The Russian software engineer Eugene Roshal developed this format. The filename extension used in this file is .rar for the data volume. For the recovery volume set, there is .rev file extension.
It is similar to a ZIP file which stores one or more files in a compressed form but it is better. The creation of RAR file can only be done with commercial software like WinRAR for Windows, command-line RAR for Linux and macOS.
There are variable-length blocks in the RAR file. It is also having an introductory block and marker. There is a file header and archive header. For the additional comment, there is a closing block. The order of these blocks may vary. The most complex one is to achieve a block which has an archive and headers as well.