A domain describes a collection of users, systems, applications, networks, database servers, and any other resources that are administered with a common set of rules. Generally, a domain also encompasses a physical space like an office or multiple offices. If you are within the domain you are in a theoretically safe space and trusted. If outside, you are untrusted, so the domain would effectively be your castle with a moat around it.<\/p>\n\n\n\n

A domain controller<\/a> (DC) is a server that manages network and identity security, effectively acting as the gatekeeper for user authentication and authorization to IT resources within the domain. Domain controllers are particularly relevant<\/a> in Microsoft directory services terminology, and function as the primary mode for authenticating Windows user identities to Windows-based systems, applications, file servers, and networks. They also host Active Directory services.<\/p>\n\n\n\n