Stop running applications

[AC Question]

How do i stop open apps from running on this phone

 

[SpookDroid]

Which phone?

But in general, going into the Application Manager in your settings and finding the app you want to stop should do the trick.

 

[B. Diddy]

But unless an app seems to be misbehaving, you should probably not bother closing apps on your own--just let the system handle it. Force closing apps, either manually or by using a task killer, can be counterproductive. See these articles for more info:

RAM: What it is, how it's used, and why you shouldn't care | Android Central
http://forums.androidcentral.com/ambassador-guides-tips-how-tos/380592-guide-ram-android.html