vRealize Orchestrator contains a workflow library and a workflow engine to allow you to create and run workflows that automate orchestration processes. You run workflows on the objects of different technologies that vRealize Orchestrator accesses through a series of plug-ins.
vRealize Orchestrator provides a standard set of plug-ins, including plug-ins for vCenter and vRealize Automation, to allow you to orchestrate tasks in the different environments that the plug-ins expose.
vRealize Orchestrator also presents an open architecture for plugging in external third-party applications to the orchestration platform. You can run workflows on the objects of the plugged-in technologies that you define yourself. vRealize Orchestrator connects to an authentication provider to manage user accounts and to a preconfigured PostgreSQL database to store information from the workflows that it runs. You can access vRealize Orchestrator, the objects it exposes, and the vRealize Orchestrator workflows through the vRealize Orchestrator Client, or through Web services. Monitoring and configuration of vRealize Orchestrator workflows and services is done through the vRealize Orchestrator Client and Control Center.
![The VMware vRealize Orchestrator Architecture consists of a workflow engine and a client application. The graphical representation of the architecture includes some of the default vRealize Orchestrator plug-ins (vRealize Automation, vCenter Server, XML, SSH, SQL, SMTP) and the preconfigured PostgreSQL database. It also includes the directory services or vCenter Single Sign On. The database, directory services, and the vCenter Single Sign On are connected to the workflow engine. A vCenter Server instance is connected to the platform through the vCenter Server plug-in](images/GUID-E71E6612-E970-499E-9503-FDD6C1FFC22E-high.png)