Execution States of iOS Application

At any given moment your iOS app will be in one of those states listed below

Not Running

You app will be in this state if it was not launched yet or was terminated by the system.

Inactive

This is a transition state, your app goes in Inactive state for a short time when launching it.

In this state you app is in the foreground but it is not ready yet to receive user input.

Active

This is the normal state where your app is in foreground and ready to receive user input and events

Background

The app is in background but executing code, Most apps enter this state before going to Suspended state.

If an application is launched directly in background mode then it enters this state instead of Inactive state.

Suspended

The app is in background but not executing any code.

It is still in memory and if a low memory condition occurs the system may purge apps in suspended state without notice.