What is Active Directory?
Active Directory (AD) is a technology created by Microsoft to provide network services including LDAP directory services,
Kerberos based authentication, DNS naming, secure access to resources, and more. Active Directory uses a single Jet database
which a variety of services and applications can use to access and store a variety of information. Active Directory is used by
system administrators to store information about users, assign security policies, and deploy software. AD is used in many
different types and size of environments from the very small (a dozen users) to hundreds of thousands of users in a global
In this tutorial, you will learn the basic structure of Active Directory, gain an understanding of how Active Directory works, learn
how to install Active Directory, and learn the components of AD.
This tutorial is divided into these sections:
What is Active Directory:
An overview of Active Directory and its use in technology environments.
Active Directory Structure:
Learn the basics of AD, its components (such as domains, domain controllers, trust relationships,
forests, organizational units, etc), hierarchies within AD, and DNS.
How to Install Active Directory:
Active Directory installation is not complex in its process, but can be difficult in the future if
you do not plan the installation correctly. Learn the tricks and tips you need to know to properly plan an AD installation and why
administrators install AD the way they do.
This free Active Directory tutorial is not a comprehensive one on the topic, but an introduction to Active Directory and its
structure and use.
Who is This Tutorial For?
This tutorial is focused at junior system administrators and PC technicians, though it can be used by anyone seeking to increase
their knowledge about Active Directory and how it works. This tutorial will teach you the building blocks of Active Directory and
how to install Active Directory. If you are pursuing an IT career, this tutorial is a good step toward system administration and
History of Active Directory
Active Directory was introduced to the world in the mid-1990s by Microsoft as a replacement for Windows NT-style user
authentication. Windows NT included a flat and non-extensible domain model which did not scale well for large corporations.
Active Directory, on the other hand, was created as a true
versus a flat user-management service that NT
had. Though it was introduced in the 1990s, it did not become a part of the Operating System until Windows 2000 Server was
released in 2000. Since then, Windows Server 2003 and Server 2008 have been introduced and Active Directory has gone under
This tutorial is based on Windows Server 2003 as it is currently the most widely installed version of the Windows network