What is a checklist on a task?

A checklist is a list of steps inside one task, ticked off as you go. The steps are not tasks: they have no owner, no date and no separate existence in reports.

Use one when the steps only make sense together and one person is doing them all — a packing list, a sequence you follow every time, the five things that make up "prepare the room".

The moment a step needs its own owner or its own deadline, it has outgrown a checklist and wants to be a subtask.