title: What is the difference between MR1 and MR2?
body: <p>I want to know the detailed difference between mapreduce 1 and mapreduce2.
  What does the inclusion of YARN actually add to Hadoop?
  I am a beginner who wants to learn Apache Hadoop.
  Can anyone suggest where to begin from.
  Also what is the cluster setup of Hadoop.
  Thank You for all the help.</p>