If you've encountered a CSV file and you're unsure what they're for, the good news is they're pretty straightforward and easy-to-use with apps you already know.

Learn how to import or export data from a Text file to convert a Text (.txt or .csv) file into an Excel (.xlsx) spreadsheet easily using this procedure.

How to import Microsoft Excel spreadsheets into Apple Numbers This procedure works with .xlsx and .xls file formats. You can also import .csv and tab-delimited files.