The PRINTER statement is used to control the destination of output from the PRINT statement.
PRINTER ON will cause all subsequent output from the PRINT statement to be redirected to the print spooler.
PRINTER OFF will cause all subsequent output from the PRINT statement to be redirected to the terminal device.
PRINTER CLOSE will act as PRINTER OFF but in addition will close all currently active spool jobs created by the active PRINTER ON statement. If the optional ON channel_number is specified then only the print job created on that channel number will be closed.