backing up photos only.
how can I back up all the photos on my MacBook? - they were edited and created in a variety of software programs. At the moment all photos are in separate albums by date but those folders are in different locations on my hard drive. Ideally I would like to identify duplicates at the same time so I could delete them. I'd like them to be placed in the same named folders on the backup drive. Ideally, I'd like to be able to continue to back up to this drive just adding in new folders. Does anyone know of a program for Mac that allows you to do this? Also I'd like to be able to work from the external hard drive to edit photos. Is this possible? I would also like to be able to back up my iphone photos to the same drive if possible. thanks
MacBook Pro 15″, macOS 10.14