The Mongol system of relay stations was called the yam. It was a network of stations where mounted couriers could change horses, obtain supplies, and carry messages rapidly across the empire.
The system built on older steppe and imperial precedents, including networks used by Chinese and Central Asian states. Under the Mongols, it was expanded and organized on an enormous scale. Stations were positioned along major routes, and local populations were often responsible for providing horses, food, lodging, or labor.
The yam was essential to governing a territory that stretched across much of Asia and later into Eastern Europe. Orders, intelligence, tax records, and diplomatic messages could travel far faster than ordinary caravans. The network also supported military campaigns and helped officials coordinate distant provinces.
Yam does not mean the Silk Road itself. The Silk Road was a broad collection of trade routes, while the yam was an administrative and communications service that sometimes used the same corridors. Ortoq, by contrast, referred to merchant partnerships connected with the Mongol elite.