A Microsoft file hosting and synchronization service.
I believe I have fixed this issue (btw found it on this thread too, a couple of pages back). Removing the Samsung app/service from your Microsoft account is only half the solution (https://account.live.com/consent/Manage). You also need remove the Microsoft account in "Connected services" from your Samsung account (https://account.samsung.com/membership/contents/services/services-gate).
More details at https://us.community.samsung.com/t5/Galaxy-S20/onedrive-camera-upload/td-p/1135421/page/2.