Active Directory is a directory service of a hierarchical structure. It is a software that organizes and provides access to information in an OS directory.

Active Directory provides different methods of storing data and makes this data available to network users and administrators. For example, the Active Directory Domain Services (AD DS) stores information about user accounts such as names, passwords, phone numbers, and so on, and enables other authorized users and administrators on the same network to access this information. The Active Directory also provides the administrator’s a centralized approach to manage user accounts, computers, and devices in a network.

Benefits of using Active Directory.

1. Centralized Data Repository: It uses a multi-master database to store the identity information of users, applications, and resources. The database is based on Joint Engine Technology (JET) database engine in which data can be modified using any alternative domain controller. With the help of the database, users can be identified in order to access resources from anywhere in the network, and administrators can authenticate and authorize organizational identities from a centralized location. It prevents identities from getting duplicated across different systems and adds administrative overhead to manage.
2. Replication of Data: In the case of multiple domain controllers in the company, if the identities are managed from a centralized server, it is necessary that each domain controller is aware of the changes that have been made to the Active Directory database. Active Directory got two types of replication. When a domain controller advertises changes made to itself to the neighboring domain controllers it is known as outbound replication. When the domain controller accepts the changes advertised by the neighboring domain controller it is known as inbound replication.
3. Security: Active Directory security features offer you to use different types of authentication, group policies, and workflows to protect the resources in the network. These technologies and methodologies benefit applications as they help them to secure the identities used within the applications. It helps the administrator to create different security rules based on departments and groups in order to protect data and workload. Users are also required to accept and follow organizational data and network security standards.
4. Auditing Capabilities: Along with advanced security policies that help in protecting identities infrastructure, periodic audits help to detect new security threats. Active Directory allows capturing and audit of data that can be related to user authentication, access violation, or directory service modifications. It helps to troubleshoot authentication and user authorization issues by collecting data from a centralized location.
5. Schema Modification: For the development of Active Directory integrated applications, it requires modifying or extending the schema of the Active Directory database. The directory service features can be accessed from different network providers with the help of Microsoft Active Directory Service Interfaces with a set of COM interfaces. The users can search for service, applications can access Active Directory objects, and developers can develop Active directory integrated application that later is published in the directory.

Info about Microsoft Exam