What is an Orphan Event?

Our Quixy platform doesn't let you create an intentional orphan event (like notifications, triggers, etc.) because you can't create an event without assigning a workflow step. But in a process that is automated, you set up events for each step of the workflow. Now, if you delete a workflow step that is connected to a certain event and don't update a workflow flow step for that event, the event becomes an orphan event.