Depending on the performance, availability, and security needs of your VMware Horizon 8 deployment, you can install a single instance of Connection Server and replicated instances of Connection Server. Replicated instances of Connection Server enables you to scale out your Horizon environment and provide high availability. Replicated instances of Connection Server enables you to scale out your Horizon environment and provide High Availability. You must install at least one instance of Connection Server.

When you install Connection Server, you select a type of installation.

Standard installation
Generates a Connection Server instance with a new Horizon LDAP configuration.
Replica installation
Generates a Connection Server instance with a Horizon LDAP configuration that is copied from an existing instance.
Enrollment Server installation
Installs an enrollment server that is required for the True SSO (single sign-on) feature, so that after users log in to VMware Workspace ONE Access, they can connect to a remote desktop or application without having to provide Active Directory credentials. The enrollment server requests the short-lived certificates that are used for authentication.
Note: Because this feature requires that a certificate authority be set up in addition to specific configuration, the installation procedure for the enrollment server is provided in the Install and Set Up an Enrollment Server section in the Horizon 8 Administration document.