The domain controller (DC) is a Windows Server host running Active Directory Domain Services. There must be at least one Primary Domain Controller (PDC) in a domain.
What separates a DC from other domain-joined computers?
- DC has Active Directory Domain Services (AD DS) role installed
- DC holds the AD DS data store
- DC replicates updates from other DCs in the AD forest
- AD heavily relies on a DNS server to provide authoritative results for this domain; typically, DC will also host the DNS server.