Not running - State of app when either app has not been launched or has been terminated (by user or by the iOS). Inactive - State of app when app doesnot execute code. Its a transition state between other states of app. When app has user recieved a call or app when to background to not running. Active - State when user is using the app Background - State when app has pressed home button and app's code is no longer executing other than for the backgroung modes or background run loop. App can stay in background for just 2 mins approximately; Otherwise iOS itself terminates the app. Suspended - State when the app's code isnot executed and is in the background. If low memory, apps in suspended state are killed.