This 15-video course explores such topics as Azure Active Directory Domain Services AD DS) and access management features in Microsoft 365. Modern businesses need modern security and safe access for users that could be easily managed by administrators, and Microsoft 365 provides those features. Key topics covered in the course include directory structures and their role in network and organizational environments; trust as the security principle defining information and access safety, established by a directory structure managed and maintained by network administrators and delivered to end users. Examine the concepts of protection and domain controllers. Learn about Azure AD Connect, pass-through authentication, Azure AD Seamless Single Sign-On, and federation using Azure AD. A closing exercise asks learners to describe features of AD DS; list examples of AD DS objects and three AD DS Forest models; list four editions of Azure AD; and list the steps for enabling password hash synchronization. The course can be used as part of the preparation for the Microsoft 365 Fundamentals (MS-900) exam.