In Azure AD (portal.azure.com | Azure Active Directory) under Monitoring, you'll find Sign-ins and Audit logs available:
![](https://static.packt-cdn.com/products/9781838984656/graphics/assets/b4e08239-7d98-4e38-acd3-0b867f6b4d37.png)
Sign-ins will show you user sign-in attempts, app usage, sign-in physical locations, and whether MFA or conditional access was utilized to sign them in.
Audit logs provide a wealth of activity logging for all changes in Azure AD including inviting users, group membership or user role changes, password updates, or policy assignments.