If you have lets say am XCEL file, once it's opened, you can then do a "save as" and you'll see a file type listed as "tab delimited" . That means that there is a tab space separating all of the pieces of information. The program can import that and will know there is a separation there. The program then knows there are columns and rows, and will ask you what field you want to assign them to. Sounds more complicated then it really is.