A domain controller (DC) (see Figure 4.5) is a server that is responsible for securely authenticating requests for accessing resources in your organization's domain. In Windows NT, there was one domain controller per domain configured as Primary Domain Controller (PDC), and all other domain controllers acted as Backup Domain Controllers (BDC). With Windows Server 2016, there are no primary and backup concepts, instead numbers are used next to DCs to identify priorities (for example, DC1 and DC2):
Figure 4.5. Accessing Domain Controllers through Active Directory Administrative Center
A server that is not acting as ...
