In this chapter, we became familiar with Apache Spark and most of its main modules. We started to use the available Spark shells and wrote our first self-contained application using the Scala and Python programming languages. Finally, we explored different ways of deploying and running Spark in cluster mode. Everything we have learned about so far is necessary for understanding the topics that are presented from Chapter 3, Extract, Transform, Load, onward. If you have any doubts about any of the presented topics, I suggest that you go back and read this chapter again before moving on.
In the next chapter, we are going to explore the basics of DL, with an emphasis on some particular implementations of multi-layer neural networks.