title: YARN: What is the difference between number-of-executors and executor-cores in Spark?
body: <p>I am learning Spark on AWS EMR. In the process I am trying to understand the difference between number of executors(--num-executors) and executor cores (--executor-cores). Can any one please tell me here?</p>
  
  <p>Also when I am trying to submit the following job, I am getting error:</p>
  
  <pre><code>spark-submit --deploy-mode cluster --master yarn --num-executors 1 --executor-cores 5   --executor-memory 1g -–conf spark.yarn.submit.waitAppCompletion=false wordcount.py s3://test/spark-example/input/input.txt s3://test/spark-example/output21
  
  Error: Unrecognized option: -–conf
  </code></pre>