For tez "tasks" represent map operations or reduce operations. A DAG is a full workflow (job) of vertices (processing of tasks) and edges (data movement between vertices). See these links for a more detailed discussion: http://hortonworks.com/blog/expressing-data-processing-in-apache-tez/ https://community.hortonworks.com/questions/32164/question-on-tez-dag-task-and-pig-on-tez.html https://cwiki.apache.org/confluence/display/TEZ/How+initial+task+parallelism+works You can see number of tasks on the console output: You can also see this in Ambari Tez view (and drill down for greater details) See this for understanding Ambari Tez view: https://docs.hortonworks.com/HDPDocuments/Ambari-2.1.2.0/bk_ambari_views_guide/content/section_using_tez_view.html ... View more