how to organize photos on iMac by moving then from one folder or album to another

As you probably know, Photos is storing each photo only once, even if we add it to several albums. The albums do not store photos, they are just an index to the photos in the library and are referencing the photos in the library. We can add photos to an album or remove photos from an album, but cannot directly move photos from one album to another.

To move a photo from Album 1 to Album to we have to use two steps:

1. add the photo to Album 2
2. then remove it from Album 1

We cannot add photos or videos to a folder, only to an album. Folders are used to group related albums or subfolders. When we drag photos to a folder, Photos will create an album with the dragged photosand add this album to the folder.