title: Doubts on RDD Spark
body: <p>I want to understand below things on RDD of Spark Concept.</p>
  
  <ol>
  <li><p>is RDD just a concept of copying require data in some node's RAM from HDFS storage to speed up the execution?</p></li>
  <li><p>if a file is splitted across the cluster then for a single flie, RDD brings all require data from other nodes? </p></li>
  <li><p>if 2nd point is correct then how it decides which node's JVM it has to execute?       how data locality works here?</p></li>
  </ol>