Active Directory Basics

Active Directory (AD) is Microsoft's directory service for Windows domain networks.

What is Active Directory?

AD provides:

• Centralized authentication - Single sign-on for users
• Authorization - Access control to resources
• Directory services - Organized database of network objects

Key Components

Domain

A logical group of network objects (computers, users, devices) that share the same AD database.

Domain Controller (DC)

Server that runs AD Domain Services. Handles:

• Authentication requests
• Stores AD database
• Replicates changes to other DCs

Organizational Units (OUs)

Containers for organizing objects within a domain. Used for:

• Applying Group Policies
• Delegating administrative control

Forest & Trees

Forest (contoso.com)
├── Tree 1: contoso.com
│   ├── us.contoso.com
│   └── eu.contoso.com
└── Tree 2: subsidiary.local

Common AD Objects

Key Ports

More AD deep-dives coming soon! 🖥️