A convoy is a group of vehicles which travels together to mutual advantage. There are a number of different types of convoys, ranging from armed convoys during war to convoys which travel together through remote areas to ensure that everyone makes it through. The practice of traveling in convoy is ancient; some of the earliest convoys were probably groups of traders who traveled together through foreign lands.

Historically, trading convoys have been used for centuries, and some of these convoys consisted of thousands of individuals traveling together. Many traders traveled in convoy across the larger deserts of Africa and the Middle East with large numbers of camels and other beasts of burden. By traveling in a large group, the traders could protect themselves from raids, and they could also sometimes negotiate better deals on the other side of the desert by bargaining together.

At sea, many convoys are military in nature. War fleets often travel in convoy to support each other, and merchant ships may convoy during a period of hostility to protect each other. During times of war, national militaries often provide convoy support to merchant fleets; stationing several destroyers to travel with a convoy, for example. Some stunning photographs of naval convoys can be seen from the Second World War, when ships traveled between Europe and the United States in huge convoys with air and sea support to defend them from German U-Boats.

On land, a convoy of military vehicles travels together to support each other for combat operations. Big rig truckers may also travel in convoy as a form of friendly brotherhood. People may also gather in a convoy to proceed through hazardous weather conditions or remote areas, to ensure that if a vehicle gets in trouble, someone will be there to notice. In such instances, other vehicles in the convoy can help with repairs, or transfer goods and passengers from the disabled vehicle to a functioning one if it becomes clear that the downed vehicle will not be able to continue the journey.

More casually, a convoy of vehicles may simply travel together to ensure that they arrive at an end destination at the same time. For example, a group of people going to a wedding or funeral together generally go in a convoy. In the case of funerals, vehicles may wear markings which identify them as part of a funeral convoy to ensure that they do not become separated. This type of convoy is also useful when only one car knows where the convoy is supposed to end up; the others cars can follow the lead vehicle to the end destination without worrying about directions.