This is a general term that refers to how sites are configured using a Content Management System. For example under Drupal’s admin interface these areas are a part of ‘site configuration’: administration menu, content authoring, development, media, people, regional and language, search and metadata, system, user interface, web services. These are some of the aspects of a CMS. How well-suited a CMS is for a particular website project depends on its site configuration and other capabilities.