• Data Store
• Schema
• Global Catalog
• Searching Mechanisms
• Replication

Domain Trees: A domain tree comprises several domains that share a common schema and configuration, forming a contiguous namespace. Domains in a tree are also linked together by trust relationships. Active Directory is a set of one or more trees.

Trees can be viewed two ways. One view is the trust relationships between domains. The other view is the namespace of the domain tree.

A collection of one or more domain trees with a common schema and implicit trust relationships between them. This arrangement would be used if you have multiple root DNS addresses.

Zone transfers may occur in response to the following different events:

• The zone refresh interval has been exceeded
• A master server notifies a secondary server of a zone change.
• A secondary DNS server service is started for the zone.
• A DNS zone transfer is manually initiated at the secondary server.

The Active Directory replaces them. Now all domain controllers share a multimaster peer-to-peer read and write relationship that hosts copies of the Active Directory.