How did the development of cuneiform enabled scholars to learn about the ancient sumerians

Cuneiform was a script that the Sumerians developed, and it is arguably the oldest writing system in the world - it allowed the Sumerians to leave written evidence for later, which we can read today. Because of this script,we can read their own words and learn about their world from their own words, rather than indirectly through archaeological finds, as was the case for all the cultures before the Sumerians, who did not leave written records