Start Activity 2 Start Activity 3 Navigate back Foreground activity Activity 3 Activity 1 Activity 2 Activity 3 Activity 2 Back Stack Activity 1 Activity 2 Activity 1 Activity 1 Activity 3 destroyed The activities are arranged in a stack,called task,in the order in which each activity is opened. When the current activity starts another,the new activity is pushed on the top of the stack and takes focus.The previous activity remains in the stack,but is stopped. Refer to: http://developer.android.com/guide/components/tasks-and-back-stack.html 55 • The activities are arranged in a stack, called task, in the order in which each activity is opened. • When the current activity starts another, the new activity is pushed on the top of the stack and takes focus. The previous activity remains in the stack, but is stopped. Refer to: http://developer.android.com/guide/components/tasks-and-back-stack.html