Question What is "Other" System storage on iOS and why is it taking up 23GB?

[Tennis987]

Hello, I am asking this because my father has an iPad 5th gen he uses regularly for work. When he was installing Microsoft Teams it said he ran out of storage. He has 400MB left of storage. I looked over his iPad, he has 6GB for the OS, only the most basic application like clock, photo, Zoom, Teams, Calendar, Reminder, etc, and 23GB of Other System Data.
Looking at iPad Storage he has roughly 700MB of photos, 500MB for MS Teams, 200MB for Zoom, and 70MB for the Mail app. The rest are small.
He had 2000 photos but that should not take up much storage, i cleared the cache and history for Safari but that removed nothing much. I deleted old text messages but that was not it. He has no backups so they do not take anything up. He has around 39GB/50GB for his iCloud Storage so i am not worried about that.
He has a Microsoft exchange account for work that syncs the standard apple Mail app to it. The only thing that caught my eye was that he had 20,000 emails in trash but I am not sure if deleting those will delete them permanently, or if they are saved on some backup his work has. I am not even sure if those emails in trash contribute to filling the storage.
Not sure what I can do to alleviate some room.

 

[Colif]

The Other/System Data category is big and varied because it’s a real catch-all category. It’s comprised of system caches, logs, Siri voices (if you’ve downloaded more than one), updates, and so much more. One of the biggest culprits for Other/System Data growing out of hand is streaming lots of music and video.

https://www.macworld.com/article/23...rage-what-is-it-and-how-do-you-delete-it.html