When an author has an explanation printed at the bottom of the page you are reading to identify a reference they made to another author’s work, what is this feature called?

I am only 10 years old, sorry  Wait this is easy question but I don’t want to answer it

monkey investigator

explanation:

he looks like one

the bazaar because it represents the inaccessible land of freedom to the narrator. mangan’s sister because she represents domesticity and routine to the narrator. the marketplace because it represents the suburban lifestyle to the narrator. the church because it represents spiritual healing and renewal to the narrator.