THESE ARE THE APPSTATES IN IOS

AppState tell that whether the app is running in foreground or background or when the state changes..
In early versions of iOS three states were supported : non running, active and in-active.
Lately, there are five application states that would be cause for the application to provide some new features or functionalities such as an application may need to continue in background..

1. ACTIVE
It means the application is presently running, executing and receiving events also..

2. INACTIVE
It means that the application is running in the foreground but it is not receiving any events.. Generally an app remains in this state for a short time.. For instance, if a call or message occurs..

3. BACKGROUND
It means that is running in background and also it is executing code. It acts just as a brief stop before an app gets suspended..

4. SUSPENDED
It means that the application is in background and no code is being executed. The system moves to this state automatically and do not notify before..

5. NOT RUNNING

It simply means that the application is not running or terminated by the system.