title: Difference between main.xml and activity_main.xml?
body: <p>I am a beginner in Android. In various tutorials, I came across the mention of main.xml residing at res.layout folder. I use the latest version of eclipse. But I couldn’t find main.xml; instead I found activity_main.xml. 
  Are these two (main.xml and activity_main.xml) the same? </p>
  
  <p>Also I couldn't find linear layout tag as tutorial says it should be a default tag present when one opens a new project. Rather I find relative layout. I think due to this, all my elements(buttons) are overlapping. Please suggest a way to fix this.</p>