A component content management system (CCMS) is a content management system (CMS) that manages content at a granular level (component) rather than at the document level. Each component represents a single topic, concept or asset (for example an image, table, product description, a procedure). The CCMS must be able to track “not only versions of topics and graphics but relationships among topics, graphics, maps, publications, and deliverables.
See this Gilbane Group white paper for a more detailed description Component Content Management – How True CCM Technology Drives the Most Compelling Content Initiatives.