Lin, domain tree, the sub-fields are active directory (Active Directory) logical unit.
Lin : comprising a single or multiple forest domain tree and a single or more child domains.
Domain tree : a common continuous windows domain name, such as: zpchcbd.com, a.zpchcbd.com, b.zpchcbd.com three in the same domain tree , the same time is called zpchcbd.com root of the tree domain , then a.zpchcbd.com, b.zpchcbd.com were to become sub-domains .
Subdomains : Any new domain is added to the domain tree are referred to as sub-domains.
Network can be divided into a tree hierarchy
The root domain of the forest : the first domain in the forest created for the root domain of the forest. And there are two predefined groups in the root domain of the forest: Enterprise Admins, Schema Admins
Enterprise Admins: you can make changes to the entire Active Directory forest, such as adding subdomains
Schema Admins: you can make changes to the Active Directory Schema entire forest
