Site and List Content Types
You create a content type at the site level. This site content type acts as a template that is independent of any specific list or library. That site content type is then available on any child site. For example, if you create a site content type at the root site of a site collection, that site content type becomes available on any site in that site collection, so that you can add it to any list in the site collection.
For more information, see Content Type Scope.
Content Type Inheritance
When you create a site content type, it becomes available on any child site. At this point, the site content type is available to be added to lists within the site, but has not actually been added to any specific site list.
To create or manage a site content type on a site, you must have Web Designer access rights to that site. Specifically, you must have the Manage Lists and Add and Customize Pages access rights on the site where the site content type resides.
To add a content type to a list, you must have List Administrator rights to that list.
When you add a site content type to a list, Windows SharePoint Services 3.0 copies a local copy of the site content type onto the list itself. This local instance is called a list content type and applies only to the list onto which it was copied.
Because Windows SharePoint Services stores a copy of the site content type as a list content type on each list to which that site content type is added, you can make changes to a list content type without affecting the site content type itself. The changes to a list content type are limited to that list and do not affect the site content type, or any other content types that inherit from that same site content type.
The following figure shows this relationship. Two site content types, Memo and Spec, are defined for a site. When the Spec content type is added to the list of a child site list, Windows SharePoint Services copies an instance of the site content type locally onto the list.
The Memo site content type is also available to be added to lists on the child site. However, this content type has not been added to the list, so no copy of it resides on the list.