Thank you for asking this question on the Microsoft Q&A Platform.
Microsoft Graph is a RESTful web API that enables you to access Microsoft Cloud service resources. After you register your app and get authentication tokens for a user or service, you can make requests to the Microsoft Graph API.
Source: https://learn.microsoft.com/en-us/graph/use-the-api
Hope this helps!
Accept Answer and Upvote, if any of the above helped, this thread can help others in the community looking for remediation for similar issues.
NOTE: To answer you as quickly as possible, please mention me in your reply.