vCenter Orchestrator and vCloud Automation Center provide the architecture that supports the Horizon vCenter Orchestrator plug-in functions.

vCenter Orchestrator plug-ins allow seamless automation between the software environment in which the workflows are executed and the products with which the workflows interact. With the Horizon vCenter Orchestrator plug-in, workflows can be exposed natively, through the vSphere Web Client, to delegated administrators, and through the vCloud Automation Center service catalog. Although entitlement, scheduling, and execution of workflows are exposed through the vSphere Web Client and vCloud Automation Center, you can customize and configure the workflows only in the vCenter Orchestrator client.

The following diagram illustrates the Horizon vCenter Orchestrator plug-in architecture.

Figure 1. Horizon vCenter Orchestrator Plug-In Architecture
The plug-in is installed in Orchestrator, but the workflows are used in vSphere Web Client and vCloud Automation Center.