I am a bit confused over how Tasks work/integrate between CRM and Invoice.

For example I would like to raise a Task in CRM as I would like to track activity and progress of a task against a contact/account and communication about that tasks.

At the same time I would like to track time spent by a contractor on that that.

So I had thought, in Invoice you open a project.
Select the Account.

Then logically, shouldn't the tasks created in CRM for that customer be able to import in Invoice?

Or are they completely separate functions that just happen to use the same name "Task"?

Thanks

Gene