A flash drive can be a good backup point. They are getting huge, you can get two terabyte models now. Windows 10 has an automatic backup ability, as well as file history management. It’s true, you can’t have too much backup, so save copies on your hard drive, on a removable flash drive, and in the cloud, if possible. But obviously, local backups are easier to restore. If your hard drive dies, and your connection to the internet as well, have backups on flash drives to ensure your precious files are safe.