group of vehicles traveling together
A convoy is a group of vehicles, typically motor vehicles or ships, traveling together for mutual support and protection. Often, a convoy is organized with armed defensive support. Civilian convoys may be organized, for example when driving through remote areas. A convoy also allows an organized group to arrive together with their equipment. They can start working together immediately, for example at an emergency. A convoy on land is sometimes called a caravan.
Convoys at sea came into widespread use when warships were made as a different kind of ship. They endangered enemy merchant ships that were not protected by friendly warships.