Earthenware is pottery made from clay that's been shaped and then baked in a special oven called a kiln. The clay used for earthenware is usually reddish or brown, and after firing at relatively low temperatures (compared to other types of pottery), it becomes hard but remains slightly porous, meaning tiny holes in the material can absorb water.

Walk into any museum with ancient artifacts and you'll likely see earthenware pots, bowls, and jars thousands of years old. Earthenware is one of humanity's oldest crafts: people discovered that wet clay could be molded into useful shapes, and when heated by fire, it became permanently hard. Ancient civilizations used earthenware for storing food, carrying water, and cooking meals.

To make earthenware waterproof, potters coat it with a glassy layer called glaze. That's why your ceramic cereal bowl doesn't leak milk everywhere. The terracotta pots used for plants are a familiar type of unglazed earthenware: notice how water slowly seeps through them.

Earthenware differs from stoneware and porcelain, which are fired at higher temperatures and become denser and stronger. But earthenware's lower firing temperature made it accessible to potters throughout history, and it remains popular today for dishes, decorative tiles, and garden pots.