Is this how caching works in cordova app?

Question

I'm developing my first android app using cordova and I'm not sure how caching works yet. The application concept is like this (perfect scenario, no plugins, no APIs, etc):

1. User opens the app

2. The app downloads and caches images according to the header Cache-Control: max-age=99999999

3. User updates and opens the app again

4. The app fetches images from cache

Where do you see problems in my concept? Is caching mechanism that cache-control header provides enough for my needs?