7.4.2. How Does It Work?
CUPS uses the Internet Print Protocol (IPP), which is based on the same HTTP protocol used by the Web. One shared virtual directory is mapped to each printer.
The CUPS configuration files are stored in /etc/cups , and the format of the main configuration file /etc/cups/cupsd.conf is very similar to the Apache configuration file (discussed in Lab 7.5, "Using the Apache Web Server "). Printer sharing is therefore enabled and disabled using Allow and Deny directives in the same way that they would be used to control access to an Apache directory. For example, global access to the printer laser0 could be configured like this:
Allow From All