These days almost every company store data such as users, emails, roles, printers, etc. in what it is call a Directory Service, providing a centralized access to company-related data that can be use across all its systems. One of the most widely used solution is Active Directory from Microsoft, since its tightly integrated with Windows OS systems. The other one LDAP, which stands for Lightweight Directory Access Protocol, has a broad range of users too since the de facto standard in Linux-based systems.