Most software that you install on archlinux have dependencies. If you want to uninstall such a software, most of dependencies will be keep installed on archlinux.
Common command to remove a software or single package in archlinux:
$sudo pacman -R packagename
That command will remove only single package, but the dependencies will be keep installed. If you install many software and remove them with "pacman -R" only, it dependencies will be useless and eat your hard disk space. So to completely remove a package and its dependencies which are not required by any other installed package, use the command below:
$sudo pacman -Rs packagename
This will remove the package and dependencies that not required by another installed package.
There are any option to remove the package in archlinux, you can see at archwiki.
But for the safest way just use two command "-R" and "-Rs". So it will not affect to another software/packages.
That's it. Enjoy.. :)