title: Android - resuming activities without killing previous activity
body: <p>I want to know how to switch between 2 activities without killing any of the 2 activities, So that I can resume it's state.
  I tried this:</p>
  
  <p>Activity1.class</p>
  
  <pre><code>    Intent i=new Intent(this,Activity2.class)
      startActivity(i);
  </code></pre>
  
  <p>Activity2.class</p>
  
  <pre><code>    Intent i=new Intent(this,Activity2.class)
      startActivity(i);
  </code></pre>
  
  <p>This codes just creates another activity and destroys the previous activity when I press back button. What I need is how can I switch activities while pausing the previous and resume to the previously paused activity without killing the activity I'm at.</p>