A CSV or comma separated value file is a standard file format for transferring data between programs. In a CSV file, each data field, or value, is separated by a comma, allowing another program to read through that file and pick out each data value between the commas. Another common format is the tab-delimited file, which uses tables instead of commas.
Many software applications provide a function for the export of data in CSV format. Check your application's Help system, and try typing the term "export" into the search box. Look for topics such as "export contacts," "export address," or "CSV."