Active Directory: Everything you Always Wanted to Know (But Were Afraid to Ask)
Microsoft Active Directory is one of the most popular directory services. As of November 2017, it was being used in 12.8 million organizations with 950 million users, as stated by Alex Simons, director of Program Management for the Microsoft Identity Division. Initially previewed in 1999, Active Directory (AD) became so ubiquitous that it was later a general term for other similar services.