What does the typical office workday look like in the 21st century?
You wake-up. You get a shower and get cleaned up (brush teeth, brush hair, etc.). You select the clothes for the day. You grab a snack or small breakfast. You then lock the home/apartment for the day, and start the car and drive to the office. You park your car. You walk to your desk, saying good morning to a few co-workers as you get to your office. You sit down and then log into the computer and open your email client (Microsoft Outlook, Lotus Notes, etc.). While your emails and calendar update, you log into your work phone and write down your voicemails to facilitate calling people back during the day.
Does this sound familiar? It does? Good, then we can work from here.
Let’s look at what you do when you sit at the desk. You logged into the computer at your desk. You typed in a username and password combination only known to you. This was given to you from the I.T. department or Human Resources when you joined the company, and you have been regularly updating the password per I.T. Security policy and guidelines.
This username and password allow you to log into company computers and get similar access to resources, regardless of the machine used or the time at which you use it. The username and password are stored on a set of servers; each username has assigned to it specific access and usage abilities that have been approved by both I.T. and your departmental supervision and management.
This username has been stored on servers. If your company has a Microsoft Windows or Microsoft Azure infrastructure, the servers that store this information for the entire organization are Active Directory servers (note: if your company has a Linux or Unix infrastructure, the servers are LDAP rather than Active Directory; but the logic is similar).
Active Directory, simply stated, is a Microsoft product that uses accounts (called objects) to control (give or revoke) permissions to other objects, groups of objects, and network resources.
For each user that logs into a Microsoft Windows account, there exists on the company network (called the domain) an object that exists in the company Active Directory (domain). When the correct username and password are selected for the domain, you are granted access to network (domain) resources based on how the object is constructed.
Objects in Active Directory are available for most users, printers, network groups, and so much more.
So, in short, Microsoft Active Directory is an organized hierarchy of objects that control access to resources.