Why not try typing CMS or Content Management System (that's a real big clue right there, by the way) into Google? Although I appreciate that taking the obvious route first and then coming to a community such as DaniWeb with specific and sensible questions would not allow you to advertise your signature links...
It is called content management system.Now a days many site use the cms.By using cms developer make the admin site with the high security.Name of Cms like a joomla,os commerce,wordpress etc..Now a days shopping site make using by the cms.
CMS - Content Management System. We can handle and manage this website in a easy process. We can add content, and remove content and update pages many features are there. We have many CMS are there for different categories.
For example Joomla is a CMS. Many business industries are using this. Any person can use this.
For a ecommerce website, yahoo stores, magento are CMS, we can mange our products update and delete through CMS. It's an easy process.