Question about IJobForEach and Parallelism

A dumb question about IJobForEach:

(from the documentation @ https://docs.unity3d.com/Packages/com.unity.entities@0.0/manual/entity_iteration_job.html):

Does this mean that:

1. The IJobForEach is scheduled as a single job, which iterates over each of the qualifying entities in sequence on a single thread, and operates in parallel to other unrelated jobs?

2. The IJobForEach creates a different job for each qualifying entity, and schedules each of these jobs to run in parallel with each other, in addition to other, unrelated jobs? <--(similar to an IJobParallelFor)

I'm...pretty sure it's #1. But I'm not 100%. Would someone mind clarifying?

Many thanks.

 

tldr:

.Schedule(...)

=> parallel

.ScheduleSingle(...)

=> one thread

more specifically, ScheduleSingle runs the job in a single thread so you can write to full range of native containers/CDFE.
Schedule processes each chunk in parallel, then inside the chunk the data is processed sequentially

 

Thank you!

Also, I am dumb. It says it right here: https://docs.unity3d.com/Packages/com.unity.entities@0.0/manual/entity_iteration_job.html