title: Apache Beam : FlatMap vs Map?
body: <p>I want to understand in which scenario that I should use FlatMap or Map. <a href="https://beam.apache.org/documentation/sdks/pydoc/0.6.0/apache_beam.transforms.html" rel="noreferrer">The documentation</a> did not seem clear to me.</p>
  
  <p>I still do not understand in which scenario I should use the transformation of FlatMap or Map.</p>
  
  <p>Could someone give me an example so I can understand their difference?</p>
  
  <p>I understand the difference of FlatMap vs Map in Spark, and however not sure if there any similarity?</p>