No, it is NOT accurate.

Pacman cannot be used to download, compile, or install AUR packages. You need the PKGBUILD file and use "makepkg -si" at the very least. If you want AUR packages, you'd install a package manager (in this context referred to as AUR helper) like "yay" that supports both official and unofficial (i.e. AUR) packages. FWIW AUR helpers are not even official packages, not even "yay" which is a popular one. You need to go out of your way to install "yay" (although it is one command away before, i.e. very easy).

TL;DR: Pacman does not download, compile, or install packages from the AUR, nor does it resolve their dependencies. "makepkg -si" builds and installs a package based on the PKGBUILD file, or use an AUR helper that overcomes the limitations of "makepkg". AUR helpers make it easy to install AUR (i.e. unofficial) packages.