RAR is compression format (like .zip, etc). It offers excellent compression for large files and excellent archive spanning/splitting capabilities. You need a program to unpack the file first. Winrar will do it, but it is not free. However, 7-Zip will unpack RAR files and is free. The only thing you can't do with 7-Zip is create a RAR archive. Once you unpack the RAR archive you will find the .psd files inside it. I frequently use rar files,but once I was amazed,reason of all my rar archives were lost for no good reason. But I entered the Google and saw there - fixed not complete rar. I was lucky and the tool solved my trouble for a minute and without payment as I keep in mind. Moreover the application showed me how it retrieves all needed documents even from corrupted archives of RAR format and so on. I am glad this tool.