Content Manager
The SDL Tridion Content Manager contains all the Components, Page objects, Templates and other items that are involved in creating the Web site for which editing is enabled.
Content Manager, short for SDL Tridion Content Manager, is the core of the SDL Tridion suite. It contains all items that are involved in producing the Web site or Web sites you can edit. When you save an item, it is saved in the Content Manager.
The Content Manager is different from the published Web site. Not all items in the Content Manager need appear on the published Web site.