A distinctive type of porcelain vessel from the Korean Joseon Dynasty, moon jars (so named because they resemble a full moon) are large round containers made for storing wine or displaying flowers.  Moon jars first appeared in the 17th century and remained popular until the mid-18th century. White was a popular color in this period because it reflected the Confucian ideals of simplicity and purity. This type of vessel is unique to Korea, never having been produced in China or Japan. Web resources here and here.

Moon Jar.  Ca. 1600 CE. Porcelain with transparent glaze. Asian Art Museum, San Francisco.