what is windows rar?

WinRAR is a tool developed by Alexandar Roshal to handle RAR files and other compression formats. It supports the following features described in its help document:

• Complete support of RAR and ZIP archives
• Highly sophisticated, original compression algorithm
• Special algorithms optimized for text, audio, graphics, 32-bit and 64-bit Intel executables compression
• Shell interface including drag-and-drop facility and wizard
• Command line interface
• Non RAR archives (7Z, ACE, ARJ, BZ2, CAB, GZ, ISO, JAR, LZH, TAR, UUE, Z) management
• Solid archiving, which can raise compression ratio by 10% - 50% over more common methods, particularly when packing a large number of small, similar files
• Multivolume archives
• Creation of self-extracting archives (also multivolume) using the default or optional SFX modules
• Recovering physically damaged archives
• Recovery volumes allowing to reconstruct missing parts of multivolume archives
• Unicode support in file names
• Other service functions, such as encryption, archive comments, error logging, etc. 
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