A Microsoft file hosting and synchronization service.
OneDrive is built into Windows. Either let OneDrive run and avoid using it, or turn off folder backup. Please do not delete any files on your computer unless you intend to get rid of them.
I suggest you turn off folder backup in the Manage Backup settings and then choose where you want to keep your files.
See how to turn off folder backup here: Back up your folders with OneDrive
By default, OneDrive backs up the Desktop, Documents, Pictures, Music, and Videos folders. If you want, you can keep these folders syncing to OneDrive but avoid OneDrive backup by not placing files in these folders.