Package Managenent

yum is a software package manager that installs, updates, and removes packages on  RPM-based systems. It automatically computes dependencies and figures out what things should occur to install packages. yum makes it easier to maintain groups of machines without having to manually update each one using rpm.
Features include:

• Support for multiple repositories
• Simple configuration
• Dependency calculation
• Fast operation
• RPM-consistent behavior
• Package group support, including multiple-repository groups
• Simple interface

yum uses an online repository by default, but you can also configure it to use a local repository of packages.