What equipment is used for loading and unloading cargo in containers or pallets?

The equipment specifically designed for loading and unloading cargo in containers or pallets is the lower deck loader. This specialized type of machinery facilitates the movement of cargo, ensuring efficient loading and unloading from the aircraft's lower deck, where containers and pallets are stored. It is engineered for accessibility to these areas and often features adjustable heights and surfaces to match the aircraft’s cargo doors, making it both safe and effective for handling freight.

Other types of equipment serve different purposes, such as lavatory trucks, which are used for servicing the aircraft’s lavatory systems, and refuelers, which are responsible for fueling the aircraft. Catering trucks, on the other hand, are utilized to deliver food and beverage supplies to the aircraft. Each of these pieces of equipment plays a vital role in airport operations, but the lower deck loader is uniquely suited for cargo handling in containers and pallets, which is why it is the correct answer.