title: Difference between back press and home button in android
body: <p>I am starting a service in my app. On click of service I am launching an activity. The service click event works fine when we go to any app and press back button and exit the app. </p>
  
  <p>But if we are in any app and then press home button and  click on the service the activity is not launched. If I click it more then 2 times,it opens the activity and sometimes it opens the app also.</p>
  
  <p>So i am unable to understand the difference between pressing back button and home button.</p>