Tuesday, June 18, 2024

What is Active Directory? – Microsoft AD Explained

Active Directory (AD) is a well-known identity provider. However, it is still a widely misunderstood Microsoft product. Most people and organizations fail to understand how it works. This database is vital in companies that require various network resources to get tasks accomplished. Microsoft invented it in the early 2000s, which was the period of modern identity management. However, the shifting landscape has made organizations and IT admins more curious about the real meaning of this database, how it works, and its significance. One frequently researched question by organizations and people interested in network development and protection is “what is active directory.”

What is Active Directory?

AD is a directory service available on Microsoft Windows server operating system. Other Microsoft solutions, such as Exchange and SharePoint Servers, also use this identity provider. It helps small, medium, and large organizations provide their employees with identities and control access to their sensitive network resources by connecting them to only the employees who need them. IT administrators also use it to manage permissions. Moreover, AD helps these firms to manage their Windows-based applications and programs. The Active Directory controls almost every activity that happens within the company’s IT environment. For example, the administrators can use it to grant the users access to laptops and servers and implement software updates and security settings.

What the AD database contains

Enterprises that use this service store their data as various objects, such as applications, shared folders, devices, and users, depending on their names and attributes. This database contains vital information about the firm’s environment, the number of computers available, the users, and their responsibilities. The AD is hierarchical, meaning that some objects might contain additional objects. Companies simplify administration by classifying the objects into groups and organizational units. For example, it might list 50 user accounts and their essential details, including job titles, names, permissions, and phone numbers. The service controls also perform authentication to ensure that every person is exactly who they claim to be on the user ID. It means that individuals whose information is not included on that list cannot access the company’s critical IT resources.

How the AD works

AD does access and controls using the idea of a domain. The domain services handle the interaction among all the profile owners within the domain. Additionally, it authenticates access whenever the users enter their username and password in a windows computer or try to connect to the company’s server. Initially, this concept was only applicable in physical locations whereby a user could access all requisite resources as long as they were on the premises. Other users who were away from the offices used VPN to access these resources because it made them appear as if they were in the location. Today, Microsoft AD is strictly for on-prem Microsoft environments. Other Microsoft settings in the cloud usually use Azure Active Directory since it offers the same services as its physical namesake. Organizations with cloud IT and on-premises environments can use the Azure AD and AD together through hybrid deployment.

The Active Directory Domain Services, also called AD DS, is the primary AD service. It is a significant component of the Windows Server operating system. An organization runs the AD DS through the assistance of several domain controllers (DCs). Changes, such as password update, inclusion of a user account, or any other personal information made on one domain container, replicates to other domain controllers since each of them has a copy of the information for the entire domain. Desktops and laptops running Active Directory windows 10 can incorporate themselves in the AD environment. However, they cannot run AD DS because it relies on various established protocols, such as Lightweight Directory Access Protocol (LDAP) and Domain Name System (DNS).

What is Azure Active Directory?

After answering the question “what is active directory,” it is vital for corporations to understand its relationship to Azure Active Directory. In today’s internet society, many companies are moving their business activities to the cloud. For this reason, Windows invented Azure active directory, commonly referred to as Azure AD, to benefit these firms. The misconception that Azure AD is a directory specifically in the cloud is common among many organizations and IT teams. The truth is that Azure AD is designed to extend the AD occurrence to the cloud, meaning that an enterprise can sync Azure AD with its on-premise AD to perform different cloud activities.

Differences between Azure and Windows Active Directory

Azure Active Directory has multiple differences from Active Directory Windows 10. Firstly, the two vary in communication whereby Windows uses LDAP while Azure AD depends on REST API. Other differences include authentication, structure, and device management. Windows AD relies on Kerberos and NTLM for verification, while Azure uses its built-in validation protocols, which are usually web-based. Thirdly, Active Directory Windows 10 has a hierarchical structure that consists of domains, trees, and forests. On the contrary, Azure AD has a flat design made up of groups and individual users. Organizations can manage Azure AD via mobile devices because it does not restrict the devices and servers that can connect to the network. With Microsoft AD, an organization has to use computers and other advanced devices because Group Policy Objects (GPOs) determine the devices that can access a particular network.

The Active Directory Structure

AD Domain Services has a hierarchical structure that is made up of three primary tiers: forests, trees, and domains. Domains are the smallest, while forests are the biggest layers.

1. Domain

A domain is a collection of different objects, such as users and computers, that belong to the same AD database. It is comparable to a tree’s branch. If a firm has branches in different locations, it has to create a separate domain for all of them. For instance, a global company should have a domain for its Canada office and a different one for the London office. It is important to understand that standard domains, a domain, and sub-domains have the same structure. For example, marketing.yourcompany.com is the same as yourcompany.com.

2. Tree

This domain tier is a collection of two or more domains organized together logically. IT experts indicate that all the domains in a domain tree “trust” each other because they are related.

3. Forest

The forest is the largest tier in Active Directory Windows 10. This level of organization contains several trees. Similar to the previous level, the trees in each forest can “trust” each other and can use the same directory schemas, domain configurations, and catalogs.

Fundamental Active Directory Features

The primary ones include;

• A schema

This characteristic is a set of rules that describes the various objects available in the directory and their attributes, constraints, and limits. This feature also indicates the format of these objects’ names. For example, it can describe the Active Directory users and computers.

• Global Catalog

This feature contains information about the objects stored in the AD. Users and IT administrators use it to locate detailed directory information or data regardless of the domain that contains it. Understanding this feature makes it easier for people who are not familiar with AD to know in Active Directory what does authorization.

• Query and Index Mechanism

This AD feature allows IT administrators and network users to find directory information fast. It also allows them to publish the objects and their characteristics or properties quickly.

• Replication Service

It distributes or disseminates directory data and information across the organization’s network. Replication is a vital process in this database. Domain controllers participate in this procedure to ensure its accuracy. They also possess a copy of all the data in the directory.

Additional Directory Services Included in Active Directory

Over time, Microsoft has included other services in the AD banner. These additional services include;

• AD lightweight directory services

This service is a lighter version of the original domain services. It eliminates complexity to allow the Active Directory users and computers to access the basic functions of the directory without using domains or domain controllers. Lightweight services are more appropriate for small organizations that use single networks.

• AD federation services

Federation services provide database users and organizations with web-based authentication and authorization amenities that only require a single sign-on when accessing the network. For example, an employee can log in to the network and receive authorization from the administrator’s network.

• AD certificate services

These services support PKI, or public key infrastructure, and provide organizations with digital certification services. Companies can also use them to create, store, authenticate, and cancel key encryption credentials. This technique is better than generating the keys locally.

• AD rights management services

The role of this service is to break down authorization until it exceeds the access granted or denied model. It limits the users’ capability to use particular files because the restrictions are usually attached to these files and not the user. When an organization starts using Active Directory rights management services, employees can access different documents but not print or copy them.

Who uses Active Directory?

An organization allows all its employees to use this database after it has leveraged it. These individuals use the system knowingly or unknowingly when accessing applications or printers, sharing different documents, and logging in to their machines at work. However, the admins are the primary users because they are responsible for operating, handling, and configuring the Active Directory. In most cases, members of the company’s IT and engineering teams qualify to be AD admins. Active Directory solutions are virtually applicable to all enterprises globally. Every organization is focusing on techniques that improve its productivity and competitiveness, and managing access to its IT resources is one of those techniques.


Overall, every organization has a team that manages and protects its valuable data in this Cybersecurity era. The Active Directory is a vital asset that can assist in this process. Employers should hire experienced IT professionals to ensure that only the right people in the firm access IT resources through identity management. They should also differentiate Active Directory Windows 10 from Azure AD in terms of authentication and device management. Determining the most appropriate program to use often depends on the amount of data the firm wants to store in the cloud.