The "polka dot jersey" is a distinctive cycling jersey awarded to the best climber in stage races, such as the Tour de France. It features a pattern of large, round dots, typically in white on a red background, making it easily recognizable. This jersey symbolizes excellence in mountain stages, where cyclists compete to accumulate points based on their performance at designated climbs. The rider with the most points at the end of the race earns the polka dot jersey, showcasing their climbing prowess and endurance in challenging terrains.