add description for packaging section

README.md

@@ -564,6 +564,8 @@ Newsletter software.
 
 **[`^        back to top        ^`](#awesome-sysadmin)**
 
+A [package manager](https://en.wikipedia.org/wiki/Package_manager) or package-management system is a collection of software tools that automates the process of installing, upgrading, configuring, and removing computer programs for a computer in a consistent manner.
+
 - [aptly](https://www.aptly.info/) - Swiss army knife for Debian repository management. ([Source Code](https://github.com/aptly-dev/aptly)) `MIT` `Go`
 - [fpm](https://fpm.readthedocs.io/en/latest/) - Versatile multi format package creator. ([Source Code](https://github.com/jordansissel/fpm)) `MIT` `Ruby`
 - [omnibus-ruby](https://github.com/chef/omnibus) - Easily create full-stack installers for your project across a variety of platforms. `Apache-2.0` `Ruby`