Software packages available for Yum download include Fedora itself and Fedora Extras from rpmfusion and rpm. All of them are maintained by the Linux community and are basically free software. All packages have independent PGP signatures, mainly for your system security. For users of Fedora core 4.0, the signature of rpm. Will be automatically imported and installed.

Yum is the Shell front-end package manager in Fedora, RedHat and CentOS. Based on RPM package management, you can automatically download and install RPM packages from designated servers, automatically handle dependencies, and install all dependent software packages at one time, without the cumbersome downloading and installation.

Yum's graphical front-end mainly includes yumex and kyum. They are not independent of yum, but the graphical front end of Yum, which means that Yumex and kyum are installed and used on the basis of Yum's installation and configuration. So when using yumex or kyum, Yum must be installed and configured first.