On Arch Linux, the official repositories are: core, extra and community. These packages are already compiled, and they are installed through `pacman`. For the most part, general users can ignore that these 3 official repositories are separate. Core contains the most critical packages, such as the kernel, boot process, networking, package management, openssh and so on. It also has stricter requirements of more thorough testing before new versions are released. Extra contains other popular package......