I copied this explanation from NextApp. To me it was the best explanation of how Android manages files without getting a headache.... Task Management Please read this section FIRST. There are a great many misconceptions about how Android works with regard to starting and stopping applications. How to Use a Task Manager Android was designed from the ground up as an operating system (OS) for mobile devices. Its built-in application and memory-management systems were engineered with battery life as one of the most critical concerns. The Android OS does not work like a desktop operating system. On a desktop OS, like Windows, Mac OS X, or Ubuntu Linux, the user is responsible for closing programs in order to keep a reasonable amount of memory available. On Android, this is not the case. The OS itself automatically removes programs from memory as memory is needed. The OS may also preload applications into memory which it thinks might soon be needed. Having lots of available empty memory is not a good thing. It takes the same amount of power to hold "nothing" in memory as it does to hold actual data. So, like every other operating system in use today, Android does its best to keep as much important/likely-to-be-used information in memory as possible. As such, using the task manager feature of SystemPanel to constantly clear memory by killing all apps is strongly NOT RECOMMENDED. This also applies to any other task killer / management program. Generally speaking, you should only "End" applications if you see one which is not working correctly. The "End All" feature can be used if your phone/device is performing poorly and you are uncertain of the cause. Process Types The SystemPanel process listing groups applications into three categories: "Active", "Inactive", and "Internal": Active applications are actually running at the present time on the device. An active application may be running in the background and not have any information currently displayed on the screen. Inactive applications have been preloaded into memory, but are not actually using up any system resources. Such applications will not consume any battery power whatsoever. The memory used by these applications can be immediately reclaimed should other applications require it. As such, there is no need to manually remove these applications, as you will see no tangible benefit from doing so. As of Android 2.2/Froyo, you may see few-to-no applications in this state. This is normal. Internal applications are those which are part of the Android operating system itself. Some of these applications may be terminated manually, but they will be immediately restarted afterward by the OS. Copyright 2009-2010 NextApp, Inc. All rights reserved.