Server daemon for the CUPS print server. More information: https://openprinting.github.io/cups/doc/man-cupsd.html.
cupsd in the background, aka. as a daemon:cupsd
cupsd on the [f]oreground:cupsd -f
cupsd on-demand (commonly used by launchd or systemd):cupsd -l
cupsd using the specified [c]upsd.conf configuration file:cupsd -c path/to/cupsd.conf
cupsd using the specified cups-file[s].conf configuration file:cupsd -s path/to/cups-files.conf
c]upsd.conf configuration file for errors:cupsd -t -c path/to/cupsd.conf
cups-file[s].conf configuration file for errors:cupsd -t -s path/to/cups-files.conf
cupsd -h