This is the first fork in the road for every other transport node in the curation: offsets, retention, consumer groups and replay only exist in the log shape, while visibility timeouts and delete-as-acknowledgement only exist in the queue shape. The outcome demands the learner can say where records are buffered and what happens to them there; without this distinction that sentence cannot even be phrased. It is also the node that makes 'without losing records' tractable, because in a queue a mistaken consume is a permanent loss and in a log it is not.
Video tutorial: Queue vs Log Delivery Models in Message Broker Systems