A CoreMedia CMS installation consists of two separate systems. The production system is used to produce your content: here you can write new articles, correct mistakes, change the page structure and much more besides. However, the key point here is that none of these changes will have a direct effect on the websites that are accessible to your readers.
In order for changes to be visible on the live system, you need to approve and then publish these changes. Before you publish your changes, however, you can use the Studio preview to see how these changes will look to your users on different devices and different times. This functionality is provided by the CAE Preview module which you can see in Figure 2.1, “Architecture of a CoreMedia CMS system”.
The two systems are separated by a firewall. This also ensures that the production environment is protected from external attacks.
To make a content item visible for your users, you must publish it to the live environment (see Section 4.7.2, “Publishing Content”). If this content item references other items that have not yet been published, its publication would result in "dead links" in the live environment. For example, a user would click on a menu link and receive an error message stating that the link target does not exist in the live environment.
To prevent this happening, CoreMedia CMS automatically checks whether a content item links to other content. If these items have already been published, then everything is OK. If not, the system checks whether the other content items have been approved. If yes, then they are also published automatically – if not, then the publication process is aborted. In this case, you will need to approve the other content items first or remove the links. The Publication window gives you precise details of what you then need to do (see Section 4.7.2, “Publishing Content”).
While CoreMedia CMS generally enforces link consistency as described in the previous paragraph, certain link properties might be set up as weak links. These links are excluded from the previously described checks.