Why does oozie launcher consume 2 containers for yarn?

Question

I use Oozie to do spark work.

I "kinda" understand that oozie dines with cartographic work related to the map, and from there sparks dine.

I don’t understand why this work consumes 2 containers of yarn?

In the resource table of the Yarn resource (called "All Applications"), I see something like the following:

ID: application_nnnnn_3456 Name: oozie: launcher ... Application Type: MAPREDUCE Container Launch: 2

ID: application_nnnnn_3457 Name: spark-app Application Type: SPARK Container Launch: 1

Is oozie-launcher hosting 2 yarn application wizards ? One for specifying MAPREDUCE and one for working Spark?