YUM stands for Yellowdog Updater Modified, which is an RPM (RedHat Package Manager) based package management tool for Linux Systems. Yum was introduced in RHEL version 5.10 onward and its deprecated up2date command. The yum command helps all Users and System Administrators to search for information about packages and then install, update, and remove all rpm-related files from systems.
The advantage of using YUM will be automatically performing the dependency resolution in a single command, even its supports to install the packages from various 3rd party repositories without any issue of dependencies. Yum was developed and released under GPL (General Public License), which means it comes under free software licenses that permit the end-user to modify the source code of the software.