Basically, the Perl 6 modules are the files on disk containing the Perl 6 code. Modules are kept in files with the .pm extension. The disk hierarchy reflects the namespace enclosure, which means that a module named X::Y corresponds to the file X/Y.pm, which will be searched for in one of the predefined catalogues or in the location specified by the -I command line option. Perl 6 has more sophisticated rules for where and how to search for the real files (e. g., it can distinguish between different versions of the same module), but let us skip that for now.
📘 Modules in Raku
N. B. Perl 6 has been renamed to Raku. Click to read more.