Screen - When Print To is set to Screen, the output is displayed on the screen (rather than being sent to a printer or to a file).
Printer - When Print To is set to Printer, select a printer from the list of available printers.
File options - When Print To is set to File, select the file option from: Acrobat File (*.pdf), Graphics File (*.png), (or Comma Delimited (*.csv), Excel File (*.xls), Open Excel File (*.xlsx) - if, and only if, the selected Report Form File's name contains the word "Export", case insensitive).
See:
Report Manager Contents