Hi donald.w.allen,
Welcome to the Apple Support Communities!
I understand that you have an unusual amount of “other” space taken up on your iPhone. To answer your question about what is stored in “other”, please read over the first attached article.
See how much storage you've used on your iPhone, iPad, and iPod touch - Apple Support
When you connect your device and select it in iTunes, you'll see your usage by content type:
- Audio: Songs, audio podcasts, audiobooks, voice memos, and ringtones
- Video: Movies, music videos, and TV shows
- Photos: Camera Roll contents, Photo Stream, and Photo Library
- Apps: Installed apps
- Books: iBooks books and PDF files
- Documents & Data: App content such as contacts, calendars, messages, emails, and their attachments, Safari Offline Reading List, and files that you've created in your apps
- Other: Settings, Siri voices, and other system data
One step I would recommend to help try and resolve this situation for you would be to back up your iPhone to iTunes and then restore from that same backup. For information on this process, please refer to the next attached articles.
How to back up your devices using iCloud or iTunes - Apple Support
Restore your device from an iCloud or iTunes backup - Apple Support
Best regards,
Joe