In summary, Pickup and Delivery route planning is the process of loading certain goods at different locations and unloading the same or different goods at different route destinations. In this case, pickups and deliveries can be connected or independent. Accordingly, deliveries can come before pickups.
In contrast, Pickup and Dropoff routing is the process of picking up an item at one location and delivering this exact item to another location. Thus, Pickup and Dropoff routing implies that one item is associated with 2 different locations and the pickup location always must be visited before the dropoff location.