Pertains to Splunk Enterprise version 5.x and earlier. As of version 6.0, this area of the product is called Settings.
A special section of Splunk Web where you can create new configurations and knowledge objects, or edit existing ones. Many of the settings in the Splunk Enterprise configuration files are also available for editing in Manager.
For more information
In the Knowledge Manager Manual (version 5.x):
In the Admin Manual (version 5.x):