It served as a path not only for items and goods being transportated from east to west and vice versa, but also as a door for foreign ideas, foreign religions (Buddhism, Manicheism, Zoroastrianism, Nestorianism, Islam), foreign cultures, foreign knowledge (Indian and Arab astronomy and mathematics)
The most important good leaving China and wandering to the west was the silk, hence the name of the road(s), but Chinese knowledge also left China to wander to the west (bookprinting, moxibustion, rhubarb, paper making, compass, porcelain).
From the begin of the 20th century on archeologists like the Swede Sven Hedin started to rediscover the old trade routes that had stretched from the Chinese capital Chang'an 長安 (modern Xi'an/Shaanxi) to Persia and the Mediterranean Sea from the Han Dynasty 漢 to the end of the Tang period.
It was through the silk road that imperial Chinese silk reached luxury-seeking Romans, who also added flavor to their food with spices from the East. Trade went two ways. Indo-Europeans may have brought written language and horse-chariots to China.