(Enterprise Deployments Only) On the Server Roles page, you assign vRealize Automation IaaS component roles to the Windows machines where you had installed the Management Agent earlier.
IaaS Windows machines may serve as primary and additional Web servers, Manager Service hosts, DEM hosts, and Agent hosts. For more about IaaS component roles, see Infrastructure as a Service.
Separation of IaaS server roles is only possible in enterprise deployments. In minimal deployments, one Windows machine performs all roles.