Active Directory is a directory service developed by Microsoft for Windows domain networks. It is a centralized, hierarchical database used to store information about network resources, such as user accounts, computers, printers, and applications. Active Directory provides a secure and efficient way to manage user access to network resources, as well as to manage and control user accounts and passwords. It also provides a single point of authentication for users, allowing them to access multiple resources with a single set of credentials. Active Directory also enables administrators to manage user access to resources, such as files, folders, and applications, as well as to manage user accounts and passwords.