Many users have asked over the past few years what "other" is on their iPhone storage and why it takes up so much room, we spoke to an Apple Store employee who explained what the "other" is referring to.
Let me start my saying that if Apple is going to offer a feature to users it should be able to explain everything clearly on your phone. That being said it's gotten better with iOS updates.
When an iPhone shows "other" this is related content stored to the iPhone. This could be one of two things on your iPhone. One it's corrupted data and you need to restore and set up your iPhone to new. The second is that is its data that it cannot be categorised. Here are some examples of data, that the iPhone can't categorise:
You have a lot of text messages with a lot of photos and videos that are taking up additional states on your phone.
You have a lot of apps that are caching. Data on your phone and you should delete and redownload those apps. Some apps will allow you to delete cache in an app backup through either iCloud or through the computer.
You're syncing data through a cloud-based service other than iCloud. Such as Google Drive and Dropbox.
We hope this helps in understanding what the "other" section is on your iPhone storage.