answer this question

Hello,

When you minimize out of an app, the app will either go into standby mode, or enter into a suspended state in which the app no longer uses system resources. In short, background apps are inactive until you use the app switcher to return to the app.

You can find out more information about the behavior of background apps by reading the following two Apple support articles

Force an app to close on your iPhone, iPad, or iPod touch - Apple Support

About Multitasking on your iPhone, iPad, and iPod touch - Apple Support

Best of luck to you.

If the camera is not the app your using, it's not doing anything. It's suspended. It isn't doing anything. There is no need to force close it (or any other app) unless there is some problem with the app.

Perhaps if you explained the reason behind this question, you'd get the best answers.

Hello,

Your inference is correct. There is no significant difference in performance when you have multiple apps open, or no apps open. Craig Federighi, Apple's SVP of software engineering has said as much in a well publicized e-mail that he exchanged with an Apple customer that was curious about the impact of open apps on system performance. You can read about Federighi's conversation in the following article

http://9to5mac.com/2016/03/10/should-you-quit-ios-apps-answer/

Actually, double-tapping the home button brings up the app switcher. The apps shown here are no really open, they are ones that you had opened before and are suspended. This just provides you a way to quickly open them again. The suspended state means you do not have to completely boot the app again.

As discussed before, it is not necessary to force closed the apps here, and as a matter of fact, it actually will cause more of a draw to open these apps again if you force them closed, since they have to open from scratch.

desmondfromnsw wrote:

But having the camera in a suspended state rather than closed means the camera hardware itself is off right

It means that you can't take pictures with the camera. What, exactly, are you trying to accomplish? If you explain, perhaps someone could give you a complete answer.

desmondfromnsw wrote:

Just curious that's all as other apps in background are active so you would imagine the camera would be too

No, all the other apps "in the background" are NOT active. In the post you marked as the solution to your question, this is clearly explained:

When you minimize out of an app, the app will either go into standby mode, or enter into a suspended state in which the app no longer uses system resources. In short, background apps are inactive until you use the app switcher to return to the app.

You can not accidentally take a photo with the camera If the camera app is suspended. It has to be the active app in the foreground in order to snap a photo.