I have used a WD hard drive as my local backup for years. It backs up my desktop, documents, pictures, music and videos. It currently shows 23.9 GB of data is backed up. I recently started using a Norton cloud account as a second backup. It backs up my pictures, music, financial files, Videos, office documents and folders. It currently shows 21.3 GB of data is backed up.
Why is there 2.6 GB difference between the two backup systems?