The default package manager for Arch Linux and its derivatives.
When installing Arch Linux, you are required to install the base package group, which includes pacman. For detailed Arch Linux installation procedures, please refer to the Arch Wiki.
Official packages:
pacman -S p7zip
Unofficial packages (User-made, e.g., via AUR):
yay -S package_name1 package_name2 ...
Search the remote repositories:
pacman -Ss package_name1 package_name2 ...
pacman -Q
Remove a specific package:
pacman -R p7zip
Remove a package and its dependencies (which are not required by any other packages):
pacman -Rsc p7zip
Perform a full system upgrade (rolling release):
pacman -Syu