title: Understanding the map/reduce process. Have few questions
body: <p>Below are the steps in serial and there are questions in between. Please correct me if I am wrong and elaborate a little bit.</p>
  
  <ul>
  <li>Client/user submits the request to the JobTracker. JobTracker is a software that resides in a name node.</li>
  <li>JobTracker divides the job into small sub-problems and gives to the TaskTracker. TaskTracker is the software that resides in data node. TaskTracker may do it again leading to multi-level tree structure.</li>
  <li>The mapping step happens only in TaskTracker not in JobTracker?</li>
  <li>Shuffle and sort takes place. Does this step takes place in Mapper step or Reducer step?</li>
  <li>The output of shuffle and sort is fed into Reducer step?</li>
  <li>The reducer step happens only in JobTracker not in TaskTracker?</li>
  <li>Reducer step i.e. JobTracker not TaskTracker combines the data and gives output to the client/user.</li>
  <li>Only 1 reducer is used for combining the result?</li>
  </ul>
  
  <p>Thanks</p>