I took the back up of my i phone today which took about 5 hours & after completion it showed the back up size 67 GB, while the amount of storage used by my phone is about 150 GB of all apps & photos. Wondering if something is missed by the back up ..?
App data but not the apps themselves is included in a backup. The following has other information about iCloud backup content: What does iCloud back up? - Apple Support
I did restore the back up on this phone from i cloud about a month ago & it restored everything same as my previous phone including all apps & their contents & all photos & videos
I have taken my back up in i cloud today
