What Does Administrative Domain (AD) Mean?
An administrative domain is a service security provider that holds security repositories and authenticates and authorizes clients with credentials safely and easily. An administrative domain may include a network of computers or a collection of networks and databases, which fall under a single common administration. These devices share common security features, which are implemented across the domain or network.
Techopedia Explains Administrative Domain (AD)
A good example is a corporate network that spans different regions and is managed by a single office or department. The components within the administrative domain operate mostly with mutual trust and treat all outside entities with suspicion. For large corporations with various offices scattered across the world, this allows the efficient sharing of data and dissemination of information, without strict security interfering with the communication network. Information is typically safe from outsiders, but the real threat comes from inside the domain, specifically when it comes to sending information to outside entities.