Help Do Apps Keep Running When......

[steveo42]

When I start an app, say I'm going to type in a text message, and before sending I hit the "back button" on the bottom of the screen, is that app still running?

Is there some EASY way to see what applications are running?

I'm a little confused as how to terminate apps and what I actually have running.

 

[Unforgiven]

I have borrowed an in depth decription from someone way smarter than I am for your reading pleasure. Just click the hide button below to see it. My short answers first.

When I start an app, say I'm going to type in a text message, and before sending I hit the "back button" on the bottom of the screen, is that app still running?

I depends on the state of the app whether it will close or not.

Is there some EASY way to see what applications are running?

Go to Settings | Apps | Running to see a list of running apps and services.

I'm a little confused as how to terminate apps and what I actually have running.

Generally you don't need to terminate apps as Android controls very well itself. It is optimized to run at near memory capacity in order to save battery and respond quickly. If an app is acting up (frozen or otherwise not playing nice) you can goto Settings | Apps | [misbehaving app] and click the Force Close button.

As I said earlier, you can get a more in depth explanation below if you wish.

Spoiler

It's best to let the system manage things, here's why:

Activities
Android apps use activites to preform tasks. For example, if you use a file manager to send a picture via email, the file manager calls the send activity within an email app, passes the file name to it and the email app sends the picture.. not the file manager. This will result in seeing the email app as "running" even though the user didn't actually launch that email app.

Smaller apps
Using activites helps developers design smaller apps. A file manager app that contains every bit of code needed to do everything a file manager does would likely be so large that no one would want to install it. Developers know that an android phone more than likely has an email app so there is no need for the developer to include email code in his/her file manager to send a picture when he/she can call an activity in an existing email app to do the job. This results in a smaller file manager app since there is no need to include email code or any other code for an activity that can be done via an app that is already present on the phone. This also alleviates redundant code. When you install an app outside of the android market, also known as sideloading, the file manager app calls the package installer (already present in Android) to install the requested app.

Running apps vs. cached apps
The "Manage Applications" list included in many android devices lists running apps as well as cached apps. Cached apps don't use any CPU or battery, they're cached so they will load faster the next time you need them. Killing cached apps results in those apps requiring more time to load the next time they are launched.

System management
By default, every android application runs in its own Linux process. Android starts the process when any of the application

 

[steveo42]

Thanks Pupkact! You've answered my questions perfectly!