Domain Controller Definition A domain controller is the server responsible for managing network and identity security requests. It acts as a gatekeeper and authenticates whether the user is authorized to access the IT resources in the domain. What is difference between Active Directory and domain controller? Active Directory is a database that stores and organizes enterprise resources as objects. You can think of Active Directory as a database that stores users and device configurations in AD DS. A domain controller, in contrast, is simply a server running Active Directory that authenticates users and devices.Nov 2, 2022 What are the 2 roles of domain controller? It authenticates users, stores user account information and enforces security policy for a domain.