Azure Active Directory provides identity and access management capabilities that enable enterprises to securely manage access to thousands of cloud, mobile, and on-premises applications using a single identity for each user. The document discusses features of Azure Active Directory including single sign-on, user lifecycle management, integration with on-premises directories, security capabilities like multifactor authentication and conditional access, and tools for IT administration and end user self-service. Case studies are presented that highlight how various large companies leverage Azure Active Directory.