In some contexts we use symbols to refer to methods by name.

Anything you might thing is an "attribute" is likely a method. E.g. on some_object.name, name is always a method. You might be confused because e.g. "attr_reader" takes symbol arguments, because it's just another method. E.g. "attr_reader :foo" defines a method named "foo" to return "@foo". ":foo" there is a Symbol representing the name "foo".