Active Directory (AD) is Microsoft's network operating system (NOS) directory, built on top of Windows 2000 and Windows Server 2003. It enables administrators to manage enterprise-wide information efficiently from a central repository that can be globally distributed. Once information about users and groups, computers and printers, and applications and services has been added to Active Directory, it can be made available for use throughout the entire network to as many or as few people as you like. The structure of the information can match the structure of your organization, and your users can query Active Directory to find the location of a printer or the email address of a colleague. With Organizational Units, you can delegate control and management of the data however you see fit. If you are like most organizations, you may have a significant amount of data (e.g., thousands of employees or computers). This may seem daunting to enter in Active Directory, but fortunately Microsoft has some very robust yet easy-to-use Application Programming Interfaces (APIs) to help facilitate data management programmatically.
This book is an introduction to Active Directory, but an introduction with a broad scope. In Part I, we cover many of the basic concepts within Active Directory to give you a good grounding in some of the fundamentals that every administrator should understand. In Part II, we focus on various design issues and methodologies, to enable you to map your organization's business requirements into your Active Directory infrastructure. Getting the design right the first time around is critical to a successful implementation, but it can be extremely difficult if you have no experience deploying Active Directory. In Part III, we cover in detail management of Active Directory programmatically through scripts based on Active Directory Service Interfaces (ADSI), ActiveX Data Objects (ADO), and Windows Management Instrumentation (WMI). No matter how good your design is, unless you can automate your environment, problems will creep in, causing decreased uniformity and reliability.
Before moving on to some of the basic components within Active Directory, we will now review how Microsoft came to the point of implementing an LDAP-based directory service to support their NOS environment.