Exam 2V0-21.20 topic 1 question 90 discussion

Join an existing vCenter Single Sign-On domain Joins a new vCenter Single Sign-On server to an existing vCenter Single Sign-On domain. You must provide the information about the vCenter Single Sign-On server to which you join the new vCenter Single Sign-On server. Enter the fully qualified domain name (FQDN) or IP address of the vCenter Single Sign-On server to join. Enter the HTTPS port to use for communication with the vCenter Single Sign-On server. Enter the domain name for the vCenter Single Sign-On you are joining, for example vsphere.local. Enter the password of the vCenter Single Sign-On administrator account. Click Next.

https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vcenter.install.doc/GUID-CA114526-A413-4219-9FA7-F5A9E9ACA357.html#GUID-CA114526-A413-4219-9FA7-F5A9E9ACA357

Joins the Platform Services Controller appliance to an existing vCenter Single Sign-On domain as a replication partner of an existing Platform Services Controller instance. You must provide the information about the partner Platform Services Controller instance that you want to join. Enter the fully qualified domain name (FQDN) or IP address of the partner Platform Services Controller instance. Enter the HTTPS port of the partner Platform Services Controller instance. Enter the vCenter Single Sign-On domain name of the partner Platform Services Controller instance. Enter the password of the vCenter Single Sign-On administrator user. Click Next. Select whether to create or join an existing vCenter Single Sign-On site.

https://docs.vmware.com/en/VMware-vSphere/6.7/com.vmware.vcenter.install.doc/GUID-A4853735-6082-4884-9612-2C83C3AEEA3B.html