What are they?

Helpers are found within a helper directory in your app file in your web app. They are basically ruby methods/classes/modules that are not associated with anything in the database(not ORM) that you can call in your controller. The example below is a helper file. Typically you would namespace these helper methods.

The image below is of a controller. Notice how you call the helper methods. You don't need to require_relative the helper file_path if you included it inside your environment.rb in your config directory