WWDC 2023 is coming on June 5 - Here is everything you need to know about the event!
How do I transfer photos from one album to another without duplicating them?
Photos will not duplicate. Albums are merely subsets of your camera roll (or photo library, if you use iCloud Photo Library.)
So photos and videos can be in multiple albums, but there will only be a single copy in the library. Hit the share icon when you are looking at a photo and you'll see an option "add to album", or open the Album and hit the large "+" icon in the last square of the album to add photos to an album.