With this feature you can set a given task on hold.
In your task list you select a given task (either double click to open or open in the task sidebar) and get the task info to show.
Then navigate to the basic settings and simply click on the button highlighted below to set the task on hold. At any time you will be able to mark the task as ‘to-do’ or ‘done’.
After this is done it will not be showing on your task list.