What we are finding are called . By definition, they are folders on a web server that are accessible to the public without needing any kind of login or password.
To understand the power of this query, you must break it down into its atomic parts. Google is not a mind reader; it is a pattern-matching engine. Each word in this string is a command. google index of series parent directory
You don't need special software to find these directories. The tools are Google's advanced search operators, often called "Google dorks". Here are the essential ones: What we are finding are called
"index of" "parent directory" "Season 1" (anime|cartoon) google index of series parent directory
Similar to Shodan but with a more academic bent. Great for finding open assets belonging to your organization.