Which file inside the CUPS configuration directory contains the definition of the printers?

The printers.conf file inside the CUPS configuration directory contains the definition of the printers. It is a text file that lists the names, locations, descriptions, and options for each printer queue. Each printer queue has a corresponding or section in the file. The file is normally located in the /etc/cups directory and is automatically updated by the cupsd (8) daemon when printers are added or modified. The file can also be edited manually, but the changes will not take effect until the cupsd daemon is restarted or the command cupsctl --reload-config is issued. References:

cups-files.conf - file and directory configuration file for cups

[printers.conf - printer configuration file for cups]