A content library instance represents a container for a set of library items. A content library item instance represents the logical object stored in the content library, which might be one or more usable files.
You create and manage the content of a content library on a single vCenter Server instance, but you can distribute the content to other vCenter Server instances. Depending on your needs, you can maintain two types of content libraries: local and subscribed. You can shape the contents of a library item and then combine several library items in a local content library. Furthermore, you can publish the library to make its content available to other users.