The term "sumerios" refers to the ancient civilization of the Sumerians, who lived in southern Mesopotamia around 4500 to 1900 BCE. They are known for creating one of the world's first writing systems, called cuneiform, which involved pressing a stylus into clay tablets. The Sumerians made significant advancements in various fields, including mathematics, astronomy, and architecture. Sumerian society was organized into city-states, such as Ur and Uruk, each governed by its own ruler. They built impressive structures, including ziggurats, which were large temple complexes. The Sumerians also developed a complex religion, worshipping multiple gods and goddesses, and their cultural achievements laid the foundation for future civilizations in the region.