3 main components of Active Directory

1) Schema
Defines objects and the information pertaining to those objects that can be stored in Active Directory
An object can be a user account, a printer, a computer, etc
Each object in active directory is defined through the schema
Schema information for objects in a domain is replicated on every DC
Each object have multiple Attributes
For a User Account, an attribute will be:
User Name
Email
Password
Address


2)Global Catalog
Stores information about every object within forest
First DC configured in a forest becomes global catalog
Can change to another DC
Purposes:

• Authentication users when they log on (Universal Group Membership)
• Uses Cached Credentials
• Forest-wide searches and access to all resources in all domains
• Replication of key AD elements
• Keeps copy of most used attributes for quick access

3)Name Space
Name resolution (DNS)

• Converts computer and domain names to IP addresses
• We need to have at least one DNS server in the domain
• Active Directory use DNS to find and interact with different network resources
• DNS and Active Directory can reside in the same physical server

Namespace

• Logical area on a network that contains directory services and named objects
• Has the ability to perform name resolution (forward and reverse namespaces within the DNS)