In Onedrive, you can share files with internal and external people.
To see which who you shared, do as following:
Open your Onedrive, for example from the waffle icon
Navigate to the file you want to check, tick it and click on the "
” button
In the "has access" panel, you will see some information.
If you click on "Manage access", you will see more details like who has access with anonymous link, from the eortc or anonymous link.
The "manage" option at the end allow you to grant access like in SharePoint
In all Onedrive, you will see an additional owner of your file called "Iland backup". This account is used to back up the data, it's not a real persons.