MIDP defines an application model to allow the resources of the device to be shared by multiple MIDlet suites in various states. Some MIDlets may be running on the foreground while others are paused on the background. Most of this MIDlet state handling is done automatically by the device, but to take full advantage of it, there are several considerations you need to take into account when developing MIDlets.
The MIDlet lifecycle defines the execution states of a MIDlet, as well as valid state transitions. The lifecycle can be considered to start when the MIDlet is installed on a device and it lasts until the MIDlet is uninstalled, but from a developer's point of view, all the important aspects of the lifecycle functions are concentrated on the time when the MIDlet is starting, active or shutting down.
When a MIDlet suite is installed on a device, its classes, resource files, arguments, and persistent storage are kept on the device and ready for use. The MIDlet(s) are managed and made available to the user via the device's Application Management Software (AMS).
In other words, as long as your application meets the MIDlet requirements, the Series 40 and Symbian platforms manage installation and uninstallation of the applications. When you follow the requirements in Implementing MIDlet lifecycle requirements, the AMS manages the MIDlet lifecycle of the application.
For more information, see the following sections: