What is cache storage and how do I reduce it?
What is cache storage and how do I reduce it?
iPad Pro 9.7-inch WiFi
These support pages should prove to be helpful:
About storage on your device and in iCloud – Apple Support
What's the difference between device storage and iCloud storage? – Apple Support
Manage your iCloud storage – Apple Support
How to check the storage on your iPhone, iPad and iPod touch – Apple Support
Clear Other storage on your iPhone or iPad - Apple Support
Clearing cached data will only temporarily release internal storage. For the most part, your iPad will automatically managed its cached storage: there are no system-wide configuration settings that control this behaviour.