YUM, the acronym for Yellowdog Updater Modified, is the software used to install, update and remove installation packages on systems that use the Red Hat Package Manager (RPM). YUM is the successor of YUP (Yellowdog Updater) and it's natively implemented as a command line tools, but some tools are available for the use with a graphical interface. YUM is distributed under GNU GPL license and it can be used on distros like Red Hat Enterprise Linux, Fedora and CentOS.