A CMS or 'Content Management System' quite literally allows you to control and manage the content within your web site - without technical training. Using this uncomplicated system you can very easily add, delete images and edit text in your web site on the fly. You can also have an unlimited number of pages and a full site-search engine.
CMS are typically used for enterprise content management (ECM) and web content management (WCM). An ECM facilitates collaboration in the workplace by integrating document management, digital asset management and records retention functionalities, and providing end users with role-based access to the organization's digital assets. A WCM facilitates collaborative authoring for websites. ECM software often includes a WCM publishing functionality, but ECM WebPages typically remain behind the organization's firewall.