https://docs.microsoft.com/en-us/sharepoint/dev/general-development/access-sharepoint-from-mobile-and-native-device-apps?redirectedfrom=MSDN
Use SharePoint REST/OData APIs for CRUD operations on SharePoint data.
These apps gain authorized access to SharePoint data by using access tokens that are issued by the Azure Control Service (ACS) in compliance with the OAuth Authentication Code flow. For more, see Authorization Code OAuth flow for SharePoint Add-ins.
