I’ve never used any past or current iterations of #iCloudPhotos, largely for not being sure where or how originals reside. I think I understand now originals are in #iCloud and optionally on devices. But I have 2 questions.

(1) When I enable it for my iPhone and iPad, I’ll eventually see images from each device show up on the other, correct?

(2) Since my photos would all end up in iCloud, does iCloud storage get doubled up use for #iCloudBackup of the phone or is it smart enough to avoid that?