jdoc statements are included in every Joomla template and indicate where the output from other parts of Joomla or its extensions should be positioned in the overall web page. A typical jdoc statement looks like this: <jdoc:include type="component" /> See the jdoc statements article for more information.
A user level on a Joomla site with access permissions to the back-end (via a separate log in) and some front-end privileges. Think of Manager users as Publishers, with Back-end access.
The official directory for all components, plugins and modules available for use with the Joomla platform. This database is maintained by the Joomla developers.