Recent vs Running vs Downloaded apps What happens when you:


Swipe out an app from Recent section?
Stop an running app by going into Running section?
Force stop an app by going into Downloaded section?


Even if you remove an app from Recent section and stop it by going to Running section, you can see the Force Stop button is enabled for app in Downloaded section. Why is it so? What kind of processes are running for that app?
Partly answering your question: What actually happens when you swipe an app out of the recent apps list? So basically:


would be like tapping the back-button from within the app until you're out of it (as opposed to just hitting the "home" button)
means killing the app by sending it a "friendly exit signal"
IMHO the same as the previous item (correct me if I'm wrong, I'm not entirely sure with this)
Force-Stop would forcefully remove all of the app's processes on system level (here the app would get no chance to interact, so it cannot even save its state or data. In easy terms: all system resources will be removed from it, so it can no longer continue to run)


For further information, also see:


Closing applications
What is the right way to close apps in Android?
How can I stop applications and services from running?
What does the “Force stop” button mean?