and then i stumble upon this site which provided me the details,
i just complied info
sources-by Chris Hoffman
Android Doesn’t Manage Processes Like Windows
Most Android users are familiar with Windows. On Windows, many programs running at one time – whether they’re windows on your desktop or applications in your system tray – can decrease your computer’s performance. Closing applications when you’re not using them can help speed up your Windows computer.
However, Android isn’t Windows and doesn’t manage processes like Windows does. Unlike on Windows, where there’s an obvious way to close applications, there’s no obvious way to “close” an Android application. This is by design and isn’t a problem. When you leave an Android app, 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.
Why Task Killers Are Bad
Proponents of task killers notice that Android is using a lot of RAM – in fact, Android stores a lot of apps in its memory, filling up the RAM! However, that isn’t a bad thing. Apps stored in your RAM can be quickly switched to without Android having to load them from its slower storage.
In summary, you shouldn’t use a task killer – if you have a misbehaving app wasting resources in the background, you should identify it and uninstall it. But don’t just remove apps from your phone or tablet’s RAM – that doesn’t help speed anything up.
Empty RAM is useless. Full RAM is RAM that is being put to good use for caching apps. 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.
Task killers think they know better than Android. They run in the background, automatically quitting apps and removing them from Android’s memory. They may also allow you to force-quit apps on your own, but you shouldn’t have to do this.
Task killers aren’t just useless – they can reduce performance. If a task killer removes an app from your RAM and you open that app again, the app will be slower to load as Android is forced to load it from your device’s storage. This will also use more battery power than if you just left the app in your RAM in the first place. Some apps will automatically restart after the task killer quits them, using more CPU and battery resources.
Whether RAM is empty or full, it takes the same amount of battery power – decreasing the amount of apps stored in RAM won’t improve your battery power or offer more CPU cycles.
hope u understood!
words of wisdom by fellow-mates
go into settings - apps and see how many running apps you have. now go to cached apps and see there, how many apps there are. you see? nearly 50% of those apps discovered by you in the processes are apps that you didn't opened ever but they are still opened and running. why? because that's how linux manages its resources. instead of having free ram for no use (what's the point of having 14gb of ram when you only use 1gb), linux fills all the ram blocks with useful apps or apps that you are running frequently so that when you call that app, it will bring it on the screen almost instantly. this my friend, is called multitasking.
and no, you are wrong. if you use a task killer killing the apps every 10 minutes, the cycles the whole system does - opening again apps and caching them, task killer closing them - results in much more functions done by CPU => more battery spent. even if you say that the battery life its the same, you are wrong. when using a task killer IT MIGHT drain your battery with 0.1% per hour. it's not that much, but IT EXIST.
oh and yeah, one thing: android has its own task killer. that's why you don't need one app to kill your other apps. because android its doing it by itself. if you don't believe me, strip down one kernel, open the init.rc file and find the values for task killer.