What's a Task Manager ?
A task manager on Android is quite the same as the one you use on your Windows PC or on a Mac for that matter
What's the difference between an Android Task Manager and the Windows Task Manager
There's absolutely no difference between the Windows Task Manager and the ones that are available on the Play Store for Android , both are concerned with informing the users about the processes that are active at a particular instant of time , and freeing up memory if required .
Is it recommended to use a Task Manager on Android ?
Absolutely NO, you should put the thought of using a Task Manager/ Task Killer on your Android device , to rest forever. Reason will be illustrated later in this post .
Why is it NOT RECOMMENDED to use a Task Manager/Task Killer for Android ?
Instead of answering the question right away, I think it might be a good idea to familiarize you guys with how Android is different from Windows when it comes to handling processes (Apps in general) .
On Windows , if you've got too many processes/applications running simultaneously , it might slow down your PC unless you have a high performance rig (eg. Alienware) . However, closing the applications you don't need can help freeing some memory and speeding things up on your computer . Also, there's an obvious option of closing your applications on Windows , and that's the "X" button located on the upper right corner of your application's windows .
However , on Android there's no way of "directly and completely" closing an app . And you might think that's a problem , but in reality it's not , Android was built from the ground up to handle processes that way . On Android 4.0+ you can dismiss an app by long pressing the home button and then swiping away the apps you're not using but still that doesn't exactly closes/kills the app, it's still running in the background .When you leave an Android app , by going back to your home screen or switching to another app , the app stays “running” in the background . In most cases , the app will be paused in the background , taking up no CPU or network resources . Some apps will continue using CPU and network resources in the background , of course – for example, music players , file-downloading programs , or apps that sync in the background .When you go back to an app you were recently using, Android “unpauses” that app and you resume where you left off . This is fast because the app is still stored in your RAM and ready to be used again .
Now people who are too concerned about speed and performance might notice that Android is using up too much of their RAM by storing apps on it and that's a good thing because the RAM is being put to good use and that was why it was shipped with your phone , caching the apps is the task of the RAM . To be honest a full RAM is better than empty RAM that's not being put to use .
If Android needs more memory , it will force-quit an app that you haven’t used in a while – this all happens automatically, without installing any task killers .
Well then why are there tonnes of Task Managers on the Play Store?
It's a hype , nothing more, of course at times your device might turn slow because of too many apps being cached on to the RAM and that's quite noticeable if you're device's specs aren't that high. But still that's not a good reason to fall for a task manager .
I'll answer this question by taking the example of the Facebook app . Facebook is one app that is always running in the background whether you're using it or not, specially when your internet is turned on. And the reason is , it was designed and developed that way. The Facebook app takes advantage of your internet connection and keeps itself updated with all your notifications and messages, and whenever you get a new notification on your profile , it just drops a toast notification on your notification bar of your Android device. Now imagine if you killed the facebook app using an Android Task Manager. What would happen? Obviously you'll miss out on all the notifications and messages, so this is one big reason for not using task managers as it hinders with the natural intended behavior of an app , and you might notice that yourself if you've got one installed, most of your apps won't provide you with the appropriate notifications and even if they do , it will be delayed .Task killers can also cause other problems by killing applications that you want running in the background — for example, if you use an alarm clock app, you may find that your task killer forced the alarm clock app to quit, preventing the alarm from going off. It's like using a rifle to kill a fly, you might resolve your problems but you're affecting other tasks .
Well then what to do if not use Task Managers? Let Apps suck my device's memory ?
No , there's no reason for you to let the apps misbehave in the background draining the precious memory and battery of your device. So there's a very good alternative to Task manger .
It's an award winning app named WatchDog . What WatchDog does is , it constantly monitors your CPU usage and informs you about the apps that are using up memory unnecessarily and the ones which are just being harmlessly stored on the RAM . And so when you finally come to know which app is responsible to slow down your device, you can kill that specific app without tampering with the others.
Now, that you know what happens when you kill an App i think it's not necessary to remind you to uninstall any task manager you have and if you really are concerned about memory, use WatchDog