Active Server Directory

An active directory (sometimes referred to as an AD) does a variety of functions including the ability to provide information on objects, helps organize these objects for easy retrieval and access, allows access by end users and administrators and allows the administrator to set security up for the directory.

An active directory can be defined as a hierarchical structure and this structure is usually broken up into three main categories, the resources which might include hardware such as printers, services for end users such as web email servers and objects which are the main functions of the domain and network.

It is interesting to note the framework for the objects. Remember that an object can be a piece of hardware such as a printer, end user or security settings set by the administrator. These objects can hold other objects within their file structure. All objects have an ID, usually an object name (folder name). In addition to these objects being able to hold other objects, every object has its own attributes which allows it to be characterized by the information which it contains. Most IT professionals call these setting or characterizations schema's.

Depending on the type of schema created for a folder, will ultimately determine how these objects are used. For instance, some objects with certain schema's can not be deleted, they can only be deactivated. Others types of schema's with certain attributes can be deleted entirely. For instance, a user object can be deleted, but the administrator object can not be deleted.

When understanding active directories, it is important to know the framework that objects can be viewed at. In fact, an active directory can be viewed at either one of three levels, these levels are called forests, trees or domains. The highest structure is called the forest because you can see all objects included within the active directory.

Within the Forest structure are trees, these structures usually hold one or more domains, going further down the structure of an active directory are single domains. To put the forest, trees and domains into perspective, consider the following example.

A large organization has many dozens of users and processes. The forest might be the entire network of end users and specific computers at a set location. Within this forest directory are now trees that hold information on specific objects such as domain controllers, program data, system, etc. Within these objects are even more objects which can then be controlled and categorized.