What “Force stop” button means?

Question

When I go to Settings->Applications->Manage Applications->Downloaded I see an application list. If I enter some applications, I see button "Force stop" active. Some applications have this button dimmed.

What does it mean? What happens if I press this button?

This button can't mean application running, since the applications with this button do not listed in Running section.

How to list all applications with Force stop button active and uninstall them?

My android is 3.2

Answer 1

As said in my comment to paco's answer, the information he gave is mostly correct: Most apps don't exit completely if you leave them, and no app should exit if you leave it via the "Home" button. Moreover, some apps have background services running which the user otherwise cannot quit.

Now there are some situations where you need an app (including its background services) to be stopped -- e.g. if you want to uninstall that app (or, in case of a system app, its updates). You will notice this when the "Force Stop" button is active, the "Uninstall" (or "Remove") button is grayed out -- but the latter gets activated when you stopped the app via "Force Stop". (If both buttons are grayed out, you can tell it's a system app, by the way -- which you cannot uninstall).

Btw: If the "Force Stop" button is grayed out ("dimmed" as you put it) it means that app is not currently running, nor has it any service running (at that moment).

Answer 2

Android maintains 4 types of applications in its memory. I dont remember all but running and cached background are 2 of them...(cached background can be accessed by clicking the hardware menu button when in the running tab and selecting the poped up option)

So though it might not be seen in the running processes, it is not entirely dead.

Mostly it shall be in the cached background prcesses.

also, about task managers..Its is not advised to use them as android has been hardcoded to manage apps efficiently.App/Task killers actually rather drain battery as after the killer kills apps, acording to the algorithm android follows,they will be started again!(and apps take up rather more memory at startup than in ideal state) thus it becomes a cycle and drains the battery.

so the force close button is active on mostly running and cached processes and may exist on a very few apps that reside in the other two types of processes!

on other apps its greyd out!

Answer 3

This button is active for apps that are running or are be running since the last time that you started your device.

Android do not kill the apps totally when you exit from it, this button is for close completely the app and remove it from the stack (apps running), also this button free the memory used by the app.

There is no way to list the apps running, also the apps running in background have this button.

There are free killer apps in the Play Store, to manage the memory of your device automatically.