Does dotted lines indicate parallel processing?

Not really, it means that the parameters on the dotted line are being mapped over by the recieving task.

what does that mean?

So

Constant[range]

is returning a range, in other words a list right?

yes

You are calling

dec.map(x=range_task)

instead of

dec(x=range_task)

yes

when you call it like

dec.map(x=range_task)

prefect iterates over the input list it receives from

range_task

, and runs a

dec

task for each element in the received list.

so it's parallelization right?

If you run your tasks parallel, sure.

It's using dask executor

nice, dask should be running tasks in parallel.

do you use prefect in production? Is it possible just to use prefect core only in production?

yes, right now I am doing that, its lacking a lot of features that are offered in prefect cloud, but I am happy with what I got

you mean you are using only prefect core you mean?