Newbie question trying to understand collection_check_boxes method

Hi, I am new to Rails, and I am trying to create checkboxes in a view. I came across this method:
https://apidock.com/rails/v4.0.2/ActionView/Helpers/FormOptionsHelper/collection_check_boxes

What I am trying to understand here is, where does this “:author_ids” method come from? Is this similar to author.ids method? I have been reading through the guide but struggling to find out where is the method coming from? Also I do not quite understand the purpose of parsing this “:name_with_initial” into the method.

Appreciate for any advice/explanation on this.