Hi Susanna,
The difference between a continuous delivery and a recurring delivery is in the way that the results are managed. A Continuous delivery will create a single delivery and add Delivery logs (broadlogs) and Tracking logs on to that same delivery each time that the activity executes. The Recurring delivery will create a new Delivery each time that that the activity executes. So for example, if you run the workflow once a week, you would end up with 52 deliveries after a year if you used a Recurring delivery activity.
Linda