packman is package management tool used in Arch linux. It is like yum on RedHat Linux, apt on Debian/Ubuntu.
If you already familiar with yum, dnf or apt, arch linux wiki have list of equivalent commands for pacman
https://wiki.archlinux.org/index.php/Pacman/Rosetta
Update all software on system
pacman -Syu
Search for a package
To search for a package, run
pacman -Ss PACKAGE_NAME
Install a package
To install a package, run
pacman -S PACKAGE_NAME
Uninstall a package
pacman -R PACKAGE_NAME