title: What exactly is the foreground in Android?
body: <p>I came across questions addressed android concepts around foreground - <a href="https://stackoverflow.com/questions/20647168/android-how-to-find-if-any-app-is-running-in-foreground">https://stackoverflow.com/questions/20647168/android-how-to-find-if-any-app-is-running-in-foreground</a>. 
  I need some clarification on the term foreground used in android. I think I have a working definition of background in android - something that happens you cannot see on the screen.
  Would foreground just be stuff that you can see and interact with on the screen. Like if I were to play a game of flappy bird, would the game itself(bird jumping over pipes) be the foreground because I can see it and interact it with. Based off that would the game music be in the background because I cannot see it?</p>