is compiz in Arch or not?
 

I was told Arch had a package. pacman says no such thing. Googled: web sites claim that arch has the package. Who is right? Is the package in Arch or not? What is the final word? How do I ascertain?

Package in question is compiz. Optimally the 0.8 branch but one takes what one can get.

Have you checked the Arch Wiki: https://wiki.archlinux.org/index.php/Compiz

it's not in arch's official repositories, but it is in the AUR:
https://aur.archlinux.org/packages/?K=compiz

If you need to, Look at:
man makepkg
https://wiki.archlinux.org/index.php/Makepkg
man pkgbuild
https://wiki.archlinux.org/index.php/PKGBUILD

Thanks for the replies. I had seen the word "AUR" appear in almost any google search result involving Arch and assumed it was akin to "aight" "senpai" or "based": just a word that gets put in there as part of the particular culture. It had never occurred to me that it had meaning. D'oh! Sorry about that. :o

So AUR means not in the official repos. Understood.

AUR == Arch User Repository