Microsoft Azure Active Directory plays a vital role in Microsoft Cloud offerings. This cloud identity concept first came up with Office 365 (formerly known as BPOS) in Microsoft cloud offerings. Azure AD comes in four editions I.e. Free, Basic, Premium P1, and Premium P2. Licensing and support also differs based on the edition. Every Azure and Office 365 subscription come up with default Azure AD Free edition. Never get confuse between the editions in Azure AD because it works based features enabled for a user. Let me list down the list of features associated with Azure AD editions and respective pricing.
Courtesy: Microsoft
Finally, let me explain you support and SLA for Microsoft Azure Active Directory. Azure AD provides 99.9% monthly availability for Basic and Premium edition and available through Azure Support, and cost you $35.27/month.