You can uninstall apps to free up memory.
When you use this method, all app settings and data are deleted from the phone memory.
Press and hold the required app until the icons start to jiggle.
Press the delete icon.
Press the Home key to return to the home screen.
When you use this method, all app settings and data are saved in the phone memory and are restored when you reinstall the app from App Store on your phone.
Press iPhone Storage.
Press the required app.
Press Offload App.