A package manager, also known as a package management system (PMS), is a program used to install, uninstall and manage software packages.
Software packages and package managers are often mentioned in connection to Unix and Unix-derived environments, such as Linux. A Linux distribution may consist of thousands of software packages. A package manager automates
Examples of package managers include Red Hat Package Manager (RPM), Yellowdog Updater, Modified (YUM) and Advanced Packaging Tool (APT).