RAR

• A RAR file is an archival file created with the WinRAR program. This program can be downloaded as a free trial for a set number of days, but it needs to be purchased and registered for continued use. WinRAR must be used to open RAR files.
  
  

ZIP

• A ZIP file is an archival file that can be created with several programs, including Freebyte Zip, WinRAR and WinZIP. It also can be created by using the "Archive" function on Macintosh operating systems. WinRAR comes as a free trial, but must be purchased to continue use after the trial expires. ZIP files can be opened with any program that can create ZIP files. It is not restricted to any one program.
  
  

Around Longer

• The first, and perhaps biggest, difference is that ZIP files have been around longer than RAR files, so there are more programs available to open and decompress ZIP files.
  
  

Compatibility

• Another difference is compatibility with operation systems. RAR files require a third-party application to open and extract the files. Microsoft Windows XP, Mac OS X and some Linux versions have a program already installed to open ZIP files.
  
  

Compression

• RAR files tend to compress smaller than ZIP files, but this varies according to the size of the files being compressed. The difference is not enough to make a huge impact when archiving files.