Why a defmacro that calls a defun?

[Eric Abrahamsen]

I'm poking through Gnus, and seeing a fair number of places with code
that looks like this:

(defmacro nnoo-define-skeleton (backend)
  `(eval-and-compile
     (nnoo-define-skeleton-1 ',backend)))

(defun nnoo-define-skeleton-1 (backend)
  ...)

What does this actually do? All I can see happening is that a quote mark
is added before the BACKEND argument in the macro. What is happening
here?

Thanks,
Eric