To track how deployed content is used and report on content usage, you must install the Knowledge Center. The Knowledge Center provides the infrastructure and tools for importing, organizing, and deploying content created in the Developer (and other applications), managing users and the content that is made available to them, and tracking and reporting. The extent of these capabilities depends on whether you are using the Standard edition (basic usage tracking and reporting) or the Professional edition (more sophisticated user and content management, content organization and deployment, usage tracking, and reporting capabilities typically found in learning content management systems).
Knowledge Center is installed on a central server, and users access it through their browser. In addition, a content repository called a content root is created in a folder on the server. This folder contains all installed content.