title: what is the difference between Oracle coherence and Hadoop HDFS
body: <p>What is the difference between Oracle Coherence and Hadoop HDFS, have read about HDFS and coherence (but nothing was clear) sounds both doing the same. 
  Whether these are different technologies addressing different problems or same Technology but different products?
  Need to know the difference and similarity between them technology wise i.e. implementation perspective, in broader way, Where these two fit in?</p>
  
  <p>Note: I am not asking for a product comparison(So no gorilla vs Shark).</p>