Installing Multilib allows the user to run and build 32-bit applications on 64-bit distributions of Arch Linux. Multilib creates a directory containing 32-bit instruction set libraries inside the folder /lib32/ which 32-bit binary applications may need when executed.
To use the multilib repository, add
[multilib] Include = /etc/pacman.d/mirrorlist
A 64-bit version of Arch Linux with Multilib installed follows a directory structure similar to Debian. The 32-bit compatible libraries are located inside /usr/lib32/ and the native 64-bit libraries are located inside /lib/ and /usr/lib/.