RAR is a file format for data compression, similar to ZIP files. RAR stands for Roshal Archive; the format is named after its creator, Eugene Roshal.
Someone sent me a .rar file and I can’t open it. What are .rar files?
A quick overview of file compression
File compression is a method of wrapping up one or more files into a single package that is often times smaller than the original(s). For example, say you wanted to e-mail a folder full of files to your friend. Instead of attaching the entire folder and all its multiple files to your e-mail message, you could compress the folder into one archive file and send that to your friend. You’ll send the e-mail faster and your friend will download it quicker because the compressed archive is smaller than all of its contents in their original form. You can also be sure that your friend receives all of the files intended for him, because there’s just one compressed file instead of many different files.
How to create and open .RAR files
In order to create (compress) and open (decompress) .RAR files, you need special software that understands the .RAR format. There are many software packages that can decompress .RAR files, but only the original WinRAR program can both compress and decompress with the .RAR format.
WinRAR is shareware, meaning that you may use it for a short trial period before having to pay a fee to continue.
Creating .RAR files with WinRAR
Encoding .RAR files refers to the procedure for creating a .RAR archive. WinRAR integrates itself directly into Windows when you install it, so creating a .RAR archive out of any selection of files or folders is as easy as right-clicking. Simply right-click on the whatever you want to compress as a .RAR file, and you’ll see WinRAR’s options in the context menu that appears.
Here, we have right clicked on a folder named “Test Folder”, and chosen to create a .RAR archive of that folder and its contents, called Test Folder.rar.
Opening .RAR files with WinRAR
Decoding .RAR files is the procedure wherein you open, or decompress a .RAR file in order to access the files it contains, in their original format. Decoding .RAR files is just as simple as encoding them — just right-click on any .RAR file to see a number of decompression options.
Here, we have right-clicked on the Test Folder.rar file and chosen to decompress its contents to a folder called “Test Folder”.
If you’d like more information about the .RAR file format, visit the RARLAB website.