difference between icloud and idrive

If you have iCloud Photos turned on they are stored in iCloud Photos. They would also be synced with any other device where you have iCloud Photos turned on. You can also view them in an internet browser in the Photos app at www.icloud.com

See: Set up and use iCloud Photos - Apple Support

If you don't have iCloud Photos turned on but do have iCloud Backup on, they would be included in iCloud Backup unless you specifically included them. You cannot view the contents of an iCloud Backup at www.icloud.com -- you can only use the backup to restore a device or set up a new device.