Content libraries are container objects for VM and vApp templates and other types of files, such as ISO images, text files, and so on. You can use the templates in the library to deploy virtual machines and vApps in the vSphere inventory. You can also use content libraries to share content across vCenter Server instances in the same or different locations. Sharing templates and files results in consistency, compliance, efficiency, and automation in deploying workloads at scale.
A content library stores and manages content in the form of library items. A single library item can consist of one file or multiple files. For example, the OVF template is a set of files (.ovf, .vmdk, and .mf). When you upload an OVF template to the library, you upload the entire set of files, but the result is a single library item of the OVF Template type.
In previous versions of vSphere, content libraries supported only OVF templates. As a result, VM and vApp templates were both converted to OVF files when you uploaded them to a content library. Starting with vSphere 6.7 Update 1, content libraries also support VM templates. So, templates in the content library can either be of the OVF Template type, or the VM Template type. vApp templates are still converted to OVF files when you upload them to a content library.
You create and manage a content library from a single vCenter Server instance, but you can distribute the content to other vCenter Server instances if HTTP(S) traffic is allowed between the two systems. The distribution of VM templates additionally requires that the respective vCenter Server instances are in Enhanced Linked Mode or Hybrid Linked Mode and that the respective hosts are connected through a network.
You can create two types of content libraries.
You can create a local content library to store and manage content in a single vCenter Server instance. If you want to share the contents of that library, you can enable publishing. When you enable publishing, other users can subscribe to the library and use its content. Alternatively, you can create subscriptions for the library, which gives you control over the distribution of content. For more information about managing a local library that has publishing enabled, see Managing a Publisher Local Library.
You can create a subscribed content library to subscribe to a published library and use its contents. You cannot upload or import items into a subscribed library. Subscribers only use the content in the published library, but it is the administrator of the published library who manages the templates. For more information about managing a subscribed library, see Managing a Subscribed Library.