Active directory objects can be classified into two broad types.
1. Security principal objects
2. Resources
Security principal objects
The objects that can be authenticated by AD are called security principal objects. These objects have unique identifiers across the domain called SIDs (security Identifier). User accounts, computer accounts and security groups are the security principal objects in AD.
Resources
Objects that are used by the security principal objects such as printers etc. are called resources in AD.
Active Directory Hierarchy: Container and Leaf Objects
Active Directory is, in fact, a hierarchical arrangement of objects. Such an arrangement is possible because AD allows some of its objects to contain other AD objects.
In other words, an AD object can either be a container or a leaf.
- Container objects: These Roles are objects that encapsulate other objects e.g. OU, Domain etc.
- Leaf objects: These objects do not encapsulate other objects. e.g. User, computer etc.