What is a RAR file
RAR is an archive format for compression, file spanning, and error recovery, much like ZIP files. RAR stands for “Roshal Archive.” It was created by Eugene Roshal (copyrighted with him and his brother), and later on licensed by win.rar GmbH. RAR files consist of two parts: the data volume set (RAR) and the recovery volume set (REV). Older versions of this archive used different extensions like RAR, R00, R01, R02 (and more). RAR files are proprietary and licensed to other freeware compression file applications. Parts of files which have become physically damaged can sometimes be repaired. RAR and ZIP files compete, but RAR files are capable of better compression rates.
Large files (up to 20 Exabytes) can be compressed using the RAR format. To accomplish this, the file will span across multiple RAR files (RAR, R01, R02, R03, etc). This enables the user to transfer the compressed data onto a removable storage device while maintaining a lossless compression. Files are extracted by programs like RARLAB, 7zip, The Unarchiver, and other freeware. The freeware which can extract RAR files cannot create files due to it not being under free software licensing. Creating RAR files needs to be done with commercial software like WinRAR. RAR v 5.0 offers the users options like multicore decompression support, faster compression and decompression, 256-bit AES encryption, improved recovery, and up to a 1GB dictionary.
Here's a small, but not exhaustive list of programs that can open RAR documents: