iirc they're just ways to search up quizzes through direct and indirect means depending on if you use the child or parent directory. Child means more indirect (or just less specific) and parent means more specific. I could be wrong.
Child directories are tags that are more specific, so the child directory of geography has things like flags or borders, which is more specific than just geography.
While a parent directory is the opposite, a parent directory of the new york tag would be something like United States, or Cities.
While a parent directory is the opposite, a parent directory of the new york tag would be something like United States, or Cities.