The Content Library in VMware vSphere 6.5 is a container object used to store VM templates, vApp templates, ISO files, and other files you can share within your network.
This article has been written for StarWind blog and can be found in this page. The article explains the configuration and the use of Content Libraries as well as the syncronization procedure to keep the content up to date with subscribed libraries.
Content Libraries benefits
A Content Library provides the capability of sharing VM Templates, vApps, ISOs and other files across multiple vCenter Server instances in the same or different locations ensuring compliancy and consistency within the infrastructure when deploying workloads.
VM templates, vApp templates and other type of files in a Content Library are defined as library items that can contain single or multiple files, such as OVF, ISO and so on. If the HTTP or HTTPS traffic is allowed between vCenter Server instances installed in your network, library items can be shared to multiple vCenter Servers.
Read the full article on StarWind blog.