This is rather an odd function to see in a Windows program, so a bit of explanation is in order.
Reports that are generated by A-Shell programs frequently are sent—by the report program—directly to a PC printer. In addition to the report, those print instructions include information for the printer, such as the name of the printer, number of copies, etc. However, APEX intercepts the report and (a) stops it from going directly to the printer, and (b) allows the user to now print the report using different parameters than the report program specified. Which is fine, and of course the user can print as he/she wishes.
But she might decide what she really wants, after looking at the report, is for it to be printed how the report program originally intended. Unfortunately she doesn't know what the report program intended; perhaps it was going to print six copies on a network printer called "Laser45."
By using this oddly-named button and function, the user can make sure that the report is handled and/or processed and/or printed as the original instructions intended.
If you do not need this function, just use the regular print operation.
