Pacman is the official software package manager for the Linux distribution Arch Linux. Currently Pacman is at version 2.9.
Pacman uses .tar .gz for all of the packages. Each of these packages contains a compiled binary built for the i686 platform. Pacman is also capable of resolving dependencies and automatically downloading and installing all necessary packages on to the local system.
Pacman is an extremely powerful package management system that is very easy to learn when adopting Arch Linux. This follows the philosophy of Arch Linux, which is to have power and manageability while still maintaining simplicity. In theory a system would only need to supply the command "pacman -Syu" regularly to have a complete updated system all the time. Compared to rpm, pacman is very easy.
Common Commands
pacman -Q - lists all the files installed with pacman or determines if the package supplied as an argument is installed
pacman -S - retrieves the package(s) supplied as an argument
pacman -R - removes the package(s) supplied as an argument
pacman -Sy - updates pacmans cached lists of the repositories
pacman -U - upgrades pacmans cached lists of the repositories
pacman -Syu - upgrades all packages if a new version is found in the repositories
pacman -Sg - prints all available package groups
pacman -A - assembles the package specified, this is often done after a package is built by ABS (Arch Build System)