What does “cart swap” primarily refer to in inflight service?

In inflight service, the term "cart swap" primarily refers to the exchange of carts for improved efficiency. This practice is often implemented to enhance the flow of service during a flight. By swapping out carts, flight attendants can ensure that they have the most appropriate cart stocked with the necessary items for the next service round, thereby reducing delays and optimizing the time spent serving passengers.

This approach allows the crew to maintain a streamlined operation, enabling them to quickly and effectively provide food and beverages to passengers. The efficiency gained through cart swaps can also help in managing space and resources on the aircraft, which is essential for maintaining overall service quality.

While the other options present relevant aspects of inflight service, they do not capture the specific function and benefit of a "cart swap." For instance, switching roles among flight attendants or changing service item locations may occur during service but do not directly pertain to the logistical and operational efficiencies achieved with a cart exchange. Additionally, altering the type of beverage offered is a service decision that does not reflect the physical operational maneuver described by "cart swap."