A RAR file is an archive that contains one or more files compressed with RAR compression. It uses a higher compression ratio than typical ZIP compression and incorporates a proprietary compression algorithm that is now used by other compressors, including 7-Zip for its .7Z files. RAR archives are used to compress files to reduce their size for transportation or storage purposes.
The RAR format was introduced in the 1990s with the release of the WinRAR compression program. Since its introduction, the format has become a common compression format along with ZIP and 7Z. While RAR files are typically created by WinRAR, they may also be compressed and extracted with a variety of utilities.
RAR files are often used to store a collection of files or files that are large in size, such as a camera raw or video file. You may encounter a RAR file via email from a coworker or friend looking to share files or you may download content in a RAR archive from a website.
The RAR compressor can also create spanned, or multi-volume, archives, which are split across several compressed files. These files typically have file extensions from .R00 to .R99, or they may all have the standard ".RAR" extension.
NOTE: The name "RAR" stands for "Roshal ARchive," which comes from Eugene Roshal, the developer of the RAR compression algorithm.