How do you play rar file?

.Rar files are basically compressed sets of files into a smaller file. (similar to .zip files) if you want to open .Rar files on a Mac you need a program called UnRarX 2. It is free

If you wish to open .Rar files on a PC you need a program called WinRar. There are many versions of it available on the web and it has a free forty day trial.