Background

Active Directory is ever-present in my company. This is some basic that I gathered on this topic.

What is Active Directory?

It is like a phone book for the organization. This phonebook can be accessed using LDAP (Lightweight Directory Access Protocol) among other things.

Any specific reason for "Company Phonebook"?

To know who's who. Other system may have their own, but usually the login tied to Active Directory.

How does this "company phonebook" looks like?

You can browse it with AD Explorer. Or plethora of other tools listed in here: https://ldap.com/ldap-tools/

Any basic pointer to browse this "phonebook"?

It is a tree
Each "node" will have "attributes". Some common attributes:

attribute usual use

dc domainComponent, like DNS domain name. example dc=example, dc=com

uid userid

cn commonName

ou organizationalUnit

Example of LDAP path (aka DN = distinguished name, I like to think of it as fullpath)
```
dc=com, dc=example, ou=singapore, ou=engineering, ou=people, uid=jdoe
```
Each node along this path will have a bunch of other attributes. For example, in node uid=jdoe, it may have the following attributes:
```
uid=jdoe
cn=John Doe
title=Chief Engineer
lastLogin=2022.02.02 02:02:02
```
What is typical usage of this

A lot. One chief usage that I used is to control access, e.g. if I want Jenkins to be available to certain groups, I can use LDAP groups.