Another feature of the Managed Metadata service is to replicate Content Types from a designated site collection hub to all other site collections sharing the Managed Metadata service. This allows Farm administrators to define a Content Type in one time in one place and have it available to use throughout the Farm. This feature would only be beneficial to Farms that have multiple site collections.
To facilitate content type replication, the Farm administrator must first configure the Managed Metadata service to point to a specific site collection as the content type hub. The following image comes from the Central Administration web site properties page of the Managed Metadata service:
The first time the Farm administrator visits this page, the Content Type hub is an empty text box that the Farm administrator types in whatever site collection path they want to use. To change it after it has been set the first time, you must use PowerShell commands.
Once the hub has been defined, the Farm administrator can then configure the Managed Metadata Service Connection to consume content types from the Content Type Gallery of the hub site collection. The following image is a screen shot of the Managed Metadata Service Connection properties:
Content types created in the site collection defined as the hub will have an extra link, Manage publishing for this content type, in the Settings group of the content type configuration page.
This link will take site collection administrators to a page where they can control publishing for that specific content type.