Why are closed Android and iOs apps still running in the background?

[AC Question]

It is commonly believed that apps running in the background drain the battery. Further, millions of smartphone users utilize task killers to close the open apps. The use of task killers is a controversial practice.

 

[belodion]

I believe that the judgment of those who have a deeper understand of operating systems than most of us, is that task-killing apps, at least for Android, are not worthwhile. I believe that they say that killed apps resurrect themselves, and so on repeatedly, causing unnecessary battery drain, as well as, for all I know, other problems.

Posted via Android Central App

 

[Golfdriver97]

For further reference: http://forums.androidcentral.com/ambassador-guides-tips-how-tos/380592-guide-ram-android.html