AD(Active Directory)

Active Directory is like the brain of an organization’s network. It’s a system developed by Microsoft to:

1. Store Information about objects: About users, computers, printers, and other resources in the network.
2. Control Access: Decide who can access which resources (e.g., files, applications, servers).
3. Centralize Management: Allow administrators to manage everything from one place.

Organizations use AD because it has

Centralised Control:

Imagine a company has 1,000 employees. Instead of managing each user’s access separately on every computer, AD does it all in one place.

Single Sign-On (SSO):

• Users log in only once with their AD credentials and gain access to all resources they’re authorised for.

Security:

• AD enforces strict security policies (ex: password rules and two-factor authentication) and makes it easy to disable a user’s account if needed.

Organized Network:

• AD organizes users, groups, computers, and devices into an easy-to-manage structure.
  

For example :

Imagine a large castle where many workers live and work. The castle has rooms, offices, libraries, and treasure vaults. The king (or queen) wanted to make sure:

1. Only authorised people could enter the castle.
2. People were allowed only into the rooms they needed.
3. Everything inside the castle was well-organized and easy to manage.

The king realised that just having guards at the doors wasn’t enough. The castle needed a system to manage all the people, permissions, and rules. And that’s how Active Directory (AD) was born.

Think of AD as a directory service that organizes and secures everything in your network. Here’s how it works:

1. The Castle's Directory:
   • AD mainly acts as a giant database that keeps track of all employees (users), departments (groups), and tools (resources) in the organization.
   • Example: "Lucy belongs to the Marketing team and has access to the Marketing Shared Drive and Email System."
2. Permissions and Rules:
   • AD sets rules to decide who can access what.
   • Example: Only the IT team can access the server room, and only HR can open the payroll folder.
3. Checks Authentication and Authorization:
   • When someone tries to log in, AD checks authentication(who are you) and authroization(What are you allowed to do)
4. Domain Controller (The Castle Guard):
   • AD uses a Domain Controller (DC)—a special server that handles all authentication requests.
   • Example: When a user logs in, the Domain Controller says, “Let me check if your username and password are correct” and gives them access if everything matches.

You may get doubt LDAP also offers centralized control, then why AD -> click here