iCloud photos storage
I Have 50Gb iCloud storage option, and using the photo app in iOS on both iPad and iPhone.
I wasunder the impression that all photos were stored in iCloud and only thumbnails were shown on my iOS devices. In this arrangement storage on iOS devices was minimised but if for example a photo was needed then clicking on it photos would instantly download the photo for editing, display, or printing etc. However I can see that 1.1 Gb of storage is used on my iPhone and 2.4 Gb used on my iPad. The iCloud storage allocated to photos is 3.7 Gb.
Why the different storage size when all should be the same and have I got some duplication which can be released?
I Am thoroughly confused but do not want to delete anything from phone/pad as it may be permanently deleted - advice please!
iOS on both devices is 9.3
iPad 2, iOS 5.1.1