About Outlook People REST
The Outlook REST API is a subset of the Microsoft Graph API, allowing you to access information regarding mail, calendar, and photos.
- In general, you should use Microsoft Graph API - as Microsoft is migrating/has migrated most API services towards Graph. However, there are a few feature differences that are key - notably that of Outlook tasks, attachment sizes of 4MB, rich notifications, and streaming notifications. Read more about the differences [here](https://docs.microsoft.com/en-us/outlook/rest/compare-graph)
- Outlook People REST REST API v2.0http://dev.office.com/docs