Active Directory (AD) is a directory service and identity management system developed by Microsoft. It is a fundamental component of the Windows Server operating system and plays a central role in managing and organizing resources, such as users, computers, and network resources, in a Windows-based network environment.
Here are the key functions and components of Active Directory:
Directory Service: AD acts as a centralized directory service that stores information about objects on a network. These objects can include users, groups, computers, printers, applications, and more.
Authentication and Authorization: AD provides authentication and authorization services, allowing users to log in to network resources and determining what actions they are permitted to perform based on their roles and permissions.
Single Sign-On (SSO): AD enables single sign-on, allowing users to log in once and access various resources across the network without having to enter their credentials repeatedly.
Domain Controller: Active Directory relies on domain controllers (DCs) to manage and store directory data. A domain controller is a Windows Server that hosts a copy of the AD database and handles authentication and authorization requests.
Domain: A domain is a logical grouping of network resources, such as users, computers, and printers, managed by Active Directory. Each domain has its own database, security policies, and trust relationships with other domains.
Forest: A forest is a collection of one or more domains that share a common schema, configuration, and global catalog. Trust relationships can exist between domains within the same forest.
Organizational Units (OUs): OUs are containers within domains used to organize and manage objects. They provide a way to apply group policies and delegate administrative control.
Group Policy: Active Directory allows administrators to define and enforce security policies and configurations across the network using Group Policy Objects (GPOs).
Replication: AD uses a replication mechanism to ensure that directory data remains consistent across all domain controllers within a domain. This ensures fault tolerance and redundancy.
Security: AD includes robust security features, including access control lists (ACLs), to control who can access and modify directory objects.
DNS Integration: AD relies on Domain Name System (DNS) for name resolution, making it essential for locating domain controllers and other network resources.
Trust Relationships: AD supports trust relationships between domains, enabling users in one domain to access resources in another domain within the same forest or in a different forest.
Active Directory is widely used in enterprise environments and is a critical component for managing user accounts, computer resources, security policies, and more in Windows-based networks. It simplifies network administration and enhances security and scalability.