It means that work should be started on an item as soon as work in the previous phase of the value stream has been completed.

It means that there should never be any buffer queues between two phases of the value stream.

It means that any worker on a team has the right to remove work from a queue if that person has the knowledge needed to perform that work.

It means that work is not started on an item in a given phase of the value stream until a) the previous phase has been completed; and b) a slot is open in the next phase or resource, such that the WIP limit is respected.