A potsherd (or pot shard or just shard) is a broken piece of pottery. Such artefacts can be of great value to an archaeologist. By analyzing various characteristics of potsherds and the context in which they are found, archaeologists can learn much about the people who made and used the original vessels. Their composition can reveal the materials, tools, and techniques available to the potter. Designs or text painted on or engraved in a potsherd can tell us about the thoughts or beliefs of the culture that created them. Changes in design or composition over time can help us determine timelines for ancient civilizations and tell us about cultural contact. Their provenance helps to reveal the uses that the creators made of different types of space. Even residue found stuck to a potsherd might help us to understand the diet or activities of their users.