There are two major possibilities for the generation of duplicate photos on a computer: 1) multiple copies of the exact same photo, which are mostly forgotten in multiple folders or different storage devices; 2) multiple photos taken in the same or very similar scenes, most of the time we don't have time or feel bother to delete those redundant ones. Duplicate photos do waste a lot of disk space, especially those with high resolution. Therefore, it is absolutely essential to remove duplicates and keep our photos collection organized.