Starting with vSphere 6.0, the deployment of the virtual environment consists of two major components that provide different sets of services, the VMware Platform Services Controller and vCenter Server. You can deploy vCenter Server with an embedded or external Platform Services Controller.
The Platform Services Controller group of infrastructure services contains vCenter Single Sign-On, License Service, Lookup Service, and VMware Certificate Authority. The services installed with the Platform Services Controller are common to the entire virtual environment. A Platform Services Controller can be connected to one or more vCenter Server instances. In a deployment that consists of more than one Platform Services Controller, the data of each service is replicated across all Platform Services Controller instances.
In vCloud Suite API client applications, you use the vCenter Single Sign-On and the Lookup Service on the Platform Services Controller to provide a range of functionality.
vCenter Server is a central administration point for ESXi hosts. The vCenter Server group of services contains vCenter Server, vSphere Web Client, Inventory Service, vSphere® Auto Deploy™, vSphere® ESXi™ Dump Collector, VMware vSphere® Syslog Collector on Windows and VMware vSphere Syslog Service for the VMware vCenter Server™ Appliance™.
vCenter Server also provides services that you can access through the vCloud Suite Endpoint.