Restarting your iPad will preserve the current state of open (but not necessarily running) Apps.
Unless Apps are intentionally force-closed, Apps will remain in one of several potential states…
- The App is “Active” - it is running running in the foreground. When you switch tasks, the App will continue to run in active state for some minutes before its resources are released and is placed into an Inactive state.
- The App is “Inactive” but remains loaded in [fast] RAM. In this state, the App can be instantly restored to an Active state - but is not consuming CPU or other resources whilst in the inactive state.
- The App is “Inactive” and unloaded. In this state, the App has been completely offloaded (releasing RAM for use by other processes) but its running state has been saved to [slow] flash memory. Returning to an App in this state will cause the App’s saved state to be reloaded from flash memory into Active RAM - without the need to re-initialise the App.
- The App has been closed. All running data has been expelled - there is no “saved” state; relaunch will reload and re-initialise the App from scratch.
Memory management is generally a juggling act - and for the most part, you should allow the OS to manage its memory space. Re-initialising an App is the slowest and most power hungry method of launching an App. Inactive Apps do consume some system resources, but by design, the required system resources to maintain this state are insignificant.
Force-closing an App releases all resources. Whilst the mechanism exists to do so (and in rare circumstances manual intervention to terminate an App may be necessary), a force close reduces system performance - and consumes considerably more power than allowing the iPad to automatically manage its memory space and resources.
To force close individual Apps, follow this procedure:
Close an app on your iPhone or iPod touch - Apple Support