Microsoft Graph API exposes a single endpoint that allows you to connect to different information from Microsoft. 

This API exposes REST APIs that allow the users to access data on the following: 

• Login using User Authentication or Application Authentication;
• Manage Microsoft Groups;
• Manage Users and Members of Groups;
• Manage Shared Calendars with Groups;
• Manage Events within Shared Calendars.

Access to a full demo to try every feautures available. 

Learn how to use by reading the full documentation available in the demo. 

Note: If you are using your personal Microsoft account you may have to change the way the application gets the code like shown in the following screenshot: