What does ".Concurrent" do, in NativeQueue.Concurrent?

I am looking at how SpaceShooterECS_Project works and I can’t figure out what “.Concurrent” does.

“The NativeHashMap.Concurrent method lets you add items in parallel from IJobParallelFor.”

I found this in the ECS Docs. So I guess its the same for NativeQueue. I’m not that sure about it though.