What is the purpose of a tow bar?

A tow bar is specifically designed to connect a tug, which is a type of vehicle, to an aircraft for the purpose of movement on the ground. This connection allows the tug to safely and effectively maneuver the aircraft in various situations, such as pushing back from the gate or repositioning on the ramp. The tow bar provides the necessary linkage and leverage to facilitate these movements while ensuring the aircraft remains stable and secure during towing operations.

The other options refer to different functions that are not relevant to the primary role of a tow bar. For instance, lifting cargo onto the aircraft involves different equipment like cargo loaders, securing baggage carts is managed with restraints or tie-downs, and unloading freight from the aircraft typically utilizes specialized loading equipment as well.