Generally about extensions
Milestone has developed various extensions. Extensions are products that extend the XProtect VMS products' functionality with additional specialized functionality.
As XProtect is an open platform, third-party extensions can also be integrated with your XProtect VMS system and add functionality to XProtect Smart Client.
Available functionality depends on the system you are using. See the complete feature list, which is available on the product overview page on the Milestone website (https://www.milestonesys.com/products/software/xprotect-comparison/).
In XProtect Smart Client, access to functionality from extensions also depends on your user permissions.