The peloton is the main group of riders in a road cycling race such as the Tour de France. The word describes the large bunch that travels together, sharing shelter from the wind and managing its collective effort.
Riding in the peloton can save substantial energy because riders behind the front line benefit from drafting. Teams use this formation strategically: domestiques may protect a leader, control the pace, chase a breakaway, or deliver a sprinter toward the finish. The group can contain most of the field, though its size changes throughout a stage.
A peloton is not the same as a breakaway, which is a smaller group that has escaped ahead. The grupetto is also different: it is a trailing group, often formed by sprinters and other riders trying to finish a difficult mountain stage within the time limit. “Caravan” usually refers to the publicity and support vehicles accompanying the race, not the riders themselves.